src/jsr166x/NavigableMap.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

package jsr166x;

import java.util.*;

/**
 * A {@link SortedMap} extended with navigation methods returning the
 * closest matches for given search targets. Methods
 * {@code lowerEntry}, {@code floorEntry}, {@code ceilingEntry},
 * and {@code higherEntry} return {@code Map.Entry} objects
 * associated with keys respectively less than, less than or equal,
 * greater than or equal, and greater than a given key, returning
 * {@code null} if there is no such key.  Similarly, methods
 * {@code lowerKey}, {@code floorKey}, {@code ceilingKey}, and
 * {@code higherKey} return only the associated keys. All of these
 * methods are designed for locating, not traversing entries.
 *
 * <p>A {@code NavigableMap} may be viewed and traversed in either
 * ascending or descending key order.  The {@code Map} methods
 * {@code keySet} and {@code entrySet} return ascending views, and
 * the additional methods {@code descendingKeySet} and
 * {@code descendingEntrySet} return descending views. The
 * performance of ascending traversals is likely to be faster than
 * descending traversals.  Notice that it is possible to perform
 * subrannge traversals in either direction using {@code SubMap}.
 *
 * <p>This interface additionally defines methods {@code firstEntry},
 * {@code pollFirstEntry}, {@code lastEntry}, and
 * {@code pollLastEntry} that return and/or remove the least and
 * greatest mappings, if any exist, else returning {@code null}.
 *
 * <p>Implementations of entry-returning methods are expected to
 * return {@code Map.Entry} pairs representing snapshots of mappings
 * at the time they were produced, and thus generally do <em>not</em>
 * support the optional {@code Entry.setValue} method. Note however
 * that it is possible to change mappings in the associated map using
 * method {@code put}.
 *
 * @author Doug Lea
 * @param <K> the type of keys maintained by this map
 * @param <V> the type of mapped values
 */
public interface NavigableMap<K,V> extends SortedMap<K,V> {
    /**
     * Returns a key-value mapping associated with the least key
     * greater than or equal to the given key, or {@code null} if there is
     * no such entry.
     *
     * @param key the key
     * @return an Entry associated with ceiling of given key, or {@code null}
     * if there is no such Entry
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public Map.Entry<K,V> ceilingEntry(K key);

    /**
     * Returns least key greater than or equal to the given key, or
     * {@code null} if there is no such key.
     *
     * @param key the key
     * @return the ceiling key, or {@code null}
     * if there is no such key
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public K ceilingKey(K key);

    /**
     * Returns a key-value mapping associated with the greatest
     * key strictly less than the given key, or {@code null} if there is no
     * such entry.
     *
     * @param key the key
     * @return an Entry with greatest key less than the given
     * key, or {@code null} if there is no such Entry
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public Map.Entry<K,V> lowerEntry(K key);

    /**
     * Returns the greatest key strictly less than the given key, or
     * {@code null} if there is no such key.
     *
     * @param key the key
     * @return the greatest key less than the given
     * key, or {@code null} if there is no such key
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public K lowerKey(K key);

    /**
     * Returns a key-value mapping associated with the greatest key
     * less than or equal to the given key, or {@code null} if there
     * is no such entry.
     *
     * @param key the key
     * @return an Entry associated with floor of given key, or {@code null}
     * if there is no such Entry
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public Map.Entry<K,V> floorEntry(K key);

    /**
     * Returns the greatest key
     * less than or equal to the given key, or {@code null} if there
     * is no such key.
     *
     * @param key the key
     * @return the floor of given key, or {@code null} if there is no
     * such key
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public K floorKey(K key);

    /**
     * Returns a key-value mapping associated with the least key
     * strictly greater than the given key, or {@code null} if there
     * is no such entry.
     *
     * @param key the key
     * @return an Entry with least key greater than the given key, or
     * {@code null} if there is no such Entry
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public Map.Entry<K,V> higherEntry(K key);

    /**
     * Returns the least key strictly greater than the given key, or
     * {@code null} if there is no such key.
     *
     * @param key the key
     * @return the least key greater than the given key, or
     * {@code null} if there is no such key
     * @throws ClassCastException if key cannot be compared with the keys
     *            currently in the map
     * @throws NullPointerException if key is {@code null} and this map
     * does not support {@code null} keys
     */
    public K higherKey(K key);

    /**
     * Returns a key-value mapping associated with the least
     * key in this map, or {@code null} if the map is empty.
     *
     * @return an Entry with least key, or {@code null}
     * if the map is empty
     */
    public Map.Entry<K,V> firstEntry();

    /**
     * Returns a key-value mapping associated with the greatest
     * key in this map, or {@code null} if the map is empty.
     *
     * @return an Entry with greatest key, or {@code null}
     * if the map is empty
     */
    public Map.Entry<K,V> lastEntry();

    /**
     * Removes and returns a key-value mapping associated with
     * the least key in this map, or {@code null} if the map is empty.
     *
     * @return the removed first entry of this map, or {@code null}
     * if the map is empty
     */
    public Map.Entry<K,V> pollFirstEntry();

    /**
     * Removes and returns a key-value mapping associated with
     * the greatest key in this map, or {@code null} if the map is empty.
     *
     * @return the removed last entry of this map, or {@code null}
     * if the map is empty
     */
    public Map.Entry<K,V> pollLastEntry();

    /**
     * Returns a set view of the keys contained in this map, in
     * descending key order.  The set is backed by the map, so changes
     * to the map are reflected in the set, and vice-versa.  If the
     * map is modified while an iteration over the set is in progress
     * (except through the iterator's own {@code remove} operation),
     * the results of the iteration are undefined.  The set supports
     * element removal, which removes the corresponding mapping from
     * the map, via the {@code Iterator.remove}, {@code Set.remove},
     * {@code removeAll} {@code retainAll}, and {@code clear}
     * operations.  It does not support the add or {@code addAll}
     * operations.
     *
     * @return a set view of the keys contained in this map
     */
    Set<K> descendingKeySet();

    /**
     * Returns a set view of the mappings contained in this map, in
     * descending key order.  Each element in the returned set is a
     * {@code Map.Entry}.  The set is backed by the map, so changes to
     * the map are reflected in the set, and vice-versa.  If the map
     * is modified while an iteration over the set is in progress
     * (except through the iterator's own {@code remove} operation,
     * or through the {@code setValue} operation on a map entry
     * returned by the iterator) the results of the iteration are
     * undefined.  The set supports element removal, which removes the
     * corresponding mapping from the map, via the
     * {@code Iterator.remove}, {@code Set.remove},
     * {@code removeAll}, {@code retainAll} and {@code clear}
     * operations.  It does not support the {@code add} or
     * {@code addAll} operations.
     *
     * @return a set view of the mappings contained in this map
     */
    Set<Map.Entry<K, V>> descendingEntrySet();

    /**
     * Returns a view of the portion of this map whose keys range from
     * {@code fromKey}, inclusive, to {@code toKey}, exclusive.  (If
     * {@code fromKey} and {@code toKey} are equal, the returned sorted map
     * is empty.)  The returned sorted map is backed by this map, so changes
     * in the returned sorted map are reflected in this map, and vice-versa.
     *
     * @param fromKey low endpoint (inclusive) of the subMap
     * @param toKey high endpoint (exclusive) of the subMap
     *
     * @return a view of the portion of this map whose keys range from
     * {@code fromKey}, inclusive, to {@code toKey}, exclusive
     *
     * @throws ClassCastException if {@code fromKey} and
     * {@code toKey} cannot be compared to one another using this
     * map's comparator (or, if the map has no comparator, using
     * natural ordering)
     * @throws IllegalArgumentException if {@code fromKey} is greater
     * than {@code toKey}
     * @throws NullPointerException if {@code fromKey} or
     * {@code toKey} is {@code null} and this map does not support
     * {@code null} keys
     */
    public NavigableMap<K,V> subMap(K fromKey, K toKey);

    /**
     * Returns a view of the portion of this map whose keys are strictly less
     * than {@code toKey}.  The returned sorted map is backed by this map, so
     * changes in the returned sorted map are reflected in this map, and
     * vice-versa.
     * @param toKey high endpoint (exclusive) of the headMap
     * @return a view of the portion of this map whose keys are strictly
     *                less than {@code toKey}
     *
     * @throws ClassCastException if {@code toKey} is not compatible
     *         with this map's comparator (or, if the map has no comparator,
     *         if {@code toKey} does not implement {@code Comparable})
     * @throws NullPointerException if {@code toKey} is {@code null}
     * and this map does not support {@code null} keys
     */
    public NavigableMap<K,V> headMap(K toKey);

    /**
     * Returns a view of the portion of this map whose keys are
     * greater than or equal to {@code fromKey}.  The returned sorted
     * map is backed by this map, so changes in the returned sorted
     * map are reflected in this map, and vice-versa.
     * @param fromKey low endpoint (inclusive) of the tailMap
     * @return a view of the portion of this map whose keys are greater
     *                than or equal to {@code fromKey}
     * @throws ClassCastException if {@code fromKey} is not compatible
     *         with this map's comparator (or, if the map has no comparator,
     *         if {@code fromKey} does not implement {@code Comparable})
     * @throws NullPointerException if {@code fromKey} is {@code null}
     * and this map does not support {@code null} keys
     */
    public NavigableMap<K,V> tailMap(K fromKey);
}
Revision:	1.11
Committed:	Wed Jan 16 00:51:11 2013 UTC (11 years, 3 months ago) by jsr166
Branch:	MAIN
Changes since 1.10:	+91 -91 lines
Log Message:	<tt> -> {@code
#	User	Rev	Content
1	dl	1.1	/*
2			* Written by Doug Lea with assistance from members of JCP JSR-166
3			* Expert Group and released to the public domain, as explained at
4	jsr166	1.6	* http://creativecommons.org/publicdomain/zero/1.0/
5	dl	1.1	*/
6
7			package jsr166x;
8
9			import java.util.*;
10
11			/**
12	dl	1.4	* A {@link SortedMap} extended with navigation methods returning the
13			* closest matches for given search targets. Methods
14	jsr166	1.11	* {@code lowerEntry}, {@code floorEntry}, {@code ceilingEntry},
15			* and {@code higherEntry} return {@code Map.Entry} objects
16	dl	1.4	* associated with keys respectively less than, less than or equal,
17			* greater than or equal, and greater than a given key, returning
18	jsr166	1.11	* {@code null} if there is no such key. Similarly, methods
19			* {@code lowerKey}, {@code floorKey}, {@code ceilingKey}, and
20			* {@code higherKey} return only the associated keys. All of these
21	dl	1.4	* methods are designed for locating, not traversing entries.
22	dl	1.3	*
23	jsr166	1.11	* <p>A {@code NavigableMap} may be viewed and traversed in either
24			* ascending or descending key order. The {@code Map} methods
25			* {@code keySet} and {@code entrySet} return ascending views, and
26			* the additional methods {@code descendingKeySet} and
27			* {@code descendingEntrySet} return descending views. The
28	dl	1.3	* performance of ascending traversals is likely to be faster than
29			* descending traversals. Notice that it is possible to perform
30	jsr166	1.11	* subrannge traversals in either direction using {@code SubMap}.
31	jsr166	1.5	*
32	jsr166	1.11	* <p>This interface additionally defines methods {@code firstEntry},
33			* {@code pollFirstEntry}, {@code lastEntry}, and
34			* {@code pollLastEntry} that return and/or remove the least and
35			* greatest mappings, if any exist, else returning {@code null}.
36	dl	1.1	*
37	jsr166	1.9	* <p>Implementations of entry-returning methods are expected to
38	jsr166	1.11	* return {@code Map.Entry} pairs representing snapshots of mappings
39	dl	1.3	* at the time they were produced, and thus generally do <em>not</em>
40	jsr166	1.11	* support the optional {@code Entry.setValue} method. Note however
41	dl	1.3	* that it is possible to change mappings in the associated map using
42	jsr166	1.11	* method {@code put}.
43	dl	1.1	*
44			* @author Doug Lea
45			* @param <K> the type of keys maintained by this map
46	jsr166	1.5	* @param <V> the type of mapped values
47	dl	1.1	*/
48			public interface NavigableMap<K,V> extends SortedMap<K,V> {
49			/**
50			* Returns a key-value mapping associated with the least key
51	jsr166	1.11	* greater than or equal to the given key, or {@code null} if there is
52	jsr166	1.5	* no such entry.
53			*
54	jsr166	1.10	* @param key the key
55	jsr166	1.11	* @return an Entry associated with ceiling of given key, or {@code null}
56	jsr166	1.10	* if there is no such Entry
57	dl	1.1	* @throws ClassCastException if key cannot be compared with the keys
58	jsr166	1.10	* currently in the map
59	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
60			* does not support {@code null} keys
61	dl	1.1	*/
62			public Map.Entry<K,V> ceilingEntry(K key);
63
64			/**
65	dl	1.3	* Returns least key greater than or equal to the given key, or
66	jsr166	1.11	* {@code null} if there is no such key.
67	jsr166	1.5	*
68	jsr166	1.10	* @param key the key
69	jsr166	1.11	* @return the ceiling key, or {@code null}
70	jsr166	1.10	* if there is no such key
71	dl	1.3	* @throws ClassCastException if key cannot be compared with the keys
72	jsr166	1.10	* currently in the map
73	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
74			* does not support {@code null} keys
75	dl	1.3	*/
76			public K ceilingKey(K key);
77
78			/**
79	dl	1.1	* Returns a key-value mapping associated with the greatest
80	jsr166	1.11	* key strictly less than the given key, or {@code null} if there is no
81	jsr166	1.5	* such entry.
82			*
83	jsr166	1.10	* @param key the key
84	dl	1.1	* @return an Entry with greatest key less than the given
85	jsr166	1.11	* key, or {@code null} if there is no such Entry
86	dl	1.1	* @throws ClassCastException if key cannot be compared with the keys
87	jsr166	1.10	* currently in the map
88	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
89			* does not support {@code null} keys
90	dl	1.1	*/
91			public Map.Entry<K,V> lowerEntry(K key);
92
93			/**
94	dl	1.3	* Returns the greatest key strictly less than the given key, or
95	jsr166	1.11	* {@code null} if there is no such key.
96	jsr166	1.5	*
97	jsr166	1.10	* @param key the key
98	dl	1.3	* @return the greatest key less than the given
99	jsr166	1.11	* key, or {@code null} if there is no such key
100	dl	1.3	* @throws ClassCastException if key cannot be compared with the keys
101	jsr166	1.10	* currently in the map
102	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
103			* does not support {@code null} keys
104	dl	1.3	*/
105			public K lowerKey(K key);
106
107			/**
108			* Returns a key-value mapping associated with the greatest key
109	jsr166	1.11	* less than or equal to the given key, or {@code null} if there
110	dl	1.3	* is no such entry.
111	jsr166	1.5	*
112	jsr166	1.10	* @param key the key
113	jsr166	1.11	* @return an Entry associated with floor of given key, or {@code null}
114	jsr166	1.10	* if there is no such Entry
115	dl	1.1	* @throws ClassCastException if key cannot be compared with the keys
116	jsr166	1.10	* currently in the map
117	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
118			* does not support {@code null} keys
119	dl	1.1	*/
120			public Map.Entry<K,V> floorEntry(K key);
121
122			/**
123	dl	1.3	* Returns the greatest key
124	jsr166	1.11	* less than or equal to the given key, or {@code null} if there
125	dl	1.3	* is no such key.
126	jsr166	1.5	*
127	jsr166	1.10	* @param key the key
128	jsr166	1.11	* @return the floor of given key, or {@code null} if there is no
129	jsr166	1.10	* such key
130	dl	1.3	* @throws ClassCastException if key cannot be compared with the keys
131	jsr166	1.10	* currently in the map
132	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
133			* does not support {@code null} keys
134	dl	1.3	*/
135			public K floorKey(K key);
136
137			/**
138			* Returns a key-value mapping associated with the least key
139	jsr166	1.11	* strictly greater than the given key, or {@code null} if there
140	dl	1.3	* is no such entry.
141	jsr166	1.5	*
142	jsr166	1.10	* @param key the key
143	dl	1.1	* @return an Entry with least key greater than the given key, or
144	jsr166	1.11	* {@code null} if there is no such Entry
145	dl	1.1	* @throws ClassCastException if key cannot be compared with the keys
146	jsr166	1.10	* currently in the map
147	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
148			* does not support {@code null} keys
149	dl	1.1	*/
150			public Map.Entry<K,V> higherEntry(K key);
151
152			/**
153	dl	1.3	* Returns the least key strictly greater than the given key, or
154	jsr166	1.11	* {@code null} if there is no such key.
155	jsr166	1.5	*
156	jsr166	1.10	* @param key the key
157	dl	1.3	* @return the least key greater than the given key, or
158	jsr166	1.11	* {@code null} if there is no such key
159	dl	1.3	* @throws ClassCastException if key cannot be compared with the keys
160	jsr166	1.10	* currently in the map
161	jsr166	1.11	* @throws NullPointerException if key is {@code null} and this map
162			* does not support {@code null} keys
163	dl	1.3	*/
164			public K higherKey(K key);
165
166			/**
167	dl	1.1	* Returns a key-value mapping associated with the least
168	jsr166	1.11	* key in this map, or {@code null} if the map is empty.
169	jsr166	1.5	*
170	jsr166	1.11	* @return an Entry with least key, or {@code null}
171	jsr166	1.10	* if the map is empty
172	dl	1.1	*/
173			public Map.Entry<K,V> firstEntry();
174
175			/**
176			* Returns a key-value mapping associated with the greatest
177	jsr166	1.11	* key in this map, or {@code null} if the map is empty.
178	jsr166	1.5	*
179	jsr166	1.11	* @return an Entry with greatest key, or {@code null}
180	jsr166	1.10	* if the map is empty
181	dl	1.1	*/
182			public Map.Entry<K,V> lastEntry();
183
184			/**
185			* Removes and returns a key-value mapping associated with
186	jsr166	1.11	* the least key in this map, or {@code null} if the map is empty.
187	jsr166	1.5	*
188	jsr166	1.11	* @return the removed first entry of this map, or {@code null}
189	jsr166	1.10	* if the map is empty
190	dl	1.1	*/
191			public Map.Entry<K,V> pollFirstEntry();
192
193			/**
194			* Removes and returns a key-value mapping associated with
195	jsr166	1.11	* the greatest key in this map, or {@code null} if the map is empty.
196	jsr166	1.5	*
197	jsr166	1.11	* @return the removed last entry of this map, or {@code null}
198	jsr166	1.10	* if the map is empty
199	dl	1.1	*/
200			public Map.Entry<K,V> pollLastEntry();
201
202			/**
203	dl	1.3	* Returns a set view of the keys contained in this map, in
204			* descending key order. The set is backed by the map, so changes
205			* to the map are reflected in the set, and vice-versa. If the
206			* map is modified while an iteration over the set is in progress
207	jsr166	1.11	* (except through the iterator's own {@code remove} operation),
208	dl	1.3	* the results of the iteration are undefined. The set supports
209			* element removal, which removes the corresponding mapping from
210	jsr166	1.11	* the map, via the {@code Iterator.remove}, {@code Set.remove},
211			* {@code removeAll} {@code retainAll}, and {@code clear}
212			* operations. It does not support the add or {@code addAll}
213	dl	1.3	* operations.
214			*
215	jsr166	1.10	* @return a set view of the keys contained in this map
216	dl	1.3	*/
217			Set<K> descendingKeySet();
218
219			/**
220			* Returns a set view of the mappings contained in this map, in
221			* descending key order. Each element in the returned set is a
222	jsr166	1.11	* {@code Map.Entry}. The set is backed by the map, so changes to
223	dl	1.3	* the map are reflected in the set, and vice-versa. If the map
224			* is modified while an iteration over the set is in progress
225	jsr166	1.11	* (except through the iterator's own {@code remove} operation,
226			* or through the {@code setValue} operation on a map entry
227	dl	1.3	* returned by the iterator) the results of the iteration are
228			* undefined. The set supports element removal, which removes the
229			* corresponding mapping from the map, via the
230	jsr166	1.11	* {@code Iterator.remove}, {@code Set.remove},
231			* {@code removeAll}, {@code retainAll} and {@code clear}
232			* operations. It does not support the {@code add} or
233			* {@code addAll} operations.
234	dl	1.3	*
235	jsr166	1.10	* @return a set view of the mappings contained in this map
236	dl	1.3	*/
237			Set<Map.Entry<K, V>> descendingEntrySet();
238
239			/**
240	dl	1.1	* Returns a view of the portion of this map whose keys range from
241	jsr166	1.11	* {@code fromKey}, inclusive, to {@code toKey}, exclusive. (If
242			* {@code fromKey} and {@code toKey} are equal, the returned sorted map
243	dl	1.1	* is empty.) The returned sorted map is backed by this map, so changes
244			* in the returned sorted map are reflected in this map, and vice-versa.
245	jsr166	1.7	*
246	jsr166	1.10	* @param fromKey low endpoint (inclusive) of the subMap
247			* @param toKey high endpoint (exclusive) of the subMap
248	dl	1.1	*
249			* @return a view of the portion of this map whose keys range from
250	jsr166	1.11	* {@code fromKey}, inclusive, to {@code toKey}, exclusive
251	dl	1.1	*
252	jsr166	1.11	* @throws ClassCastException if {@code fromKey} and
253			* {@code toKey} cannot be compared to one another using this
254	dl	1.1	* map's comparator (or, if the map has no comparator, using
255	jsr166	1.10	* natural ordering)
256	jsr166	1.11	* @throws IllegalArgumentException if {@code fromKey} is greater
257			* than {@code toKey}
258			* @throws NullPointerException if {@code fromKey} or
259			* {@code toKey} is {@code null} and this map does not support
260			* {@code null} keys
261	dl	1.1	*/
262			public NavigableMap<K,V> subMap(K fromKey, K toKey);
263
264			/**
265			* Returns a view of the portion of this map whose keys are strictly less
266	jsr166	1.11	* than {@code toKey}. The returned sorted map is backed by this map, so
267	dl	1.1	* changes in the returned sorted map are reflected in this map, and
268	jsr166	1.5	* vice-versa.
269	jsr166	1.10	* @param toKey high endpoint (exclusive) of the headMap
270	dl	1.1	* @return a view of the portion of this map whose keys are strictly
271	jsr166	1.11	* less than {@code toKey}
272	dl	1.1	*
273	jsr166	1.11	* @throws ClassCastException if {@code toKey} is not compatible
274	dl	1.1	* with this map's comparator (or, if the map has no comparator,
275	jsr166	1.11	* if {@code toKey} does not implement {@code Comparable})
276			* @throws NullPointerException if {@code toKey} is {@code null}
277			* and this map does not support {@code null} keys
278	dl	1.1	*/
279			public NavigableMap<K,V> headMap(K toKey);
280
281			/**
282			* Returns a view of the portion of this map whose keys are
283	jsr166	1.11	* greater than or equal to {@code fromKey}. The returned sorted
284	dl	1.1	* map is backed by this map, so changes in the returned sorted
285			* map are reflected in this map, and vice-versa.
286	jsr166	1.10	* @param fromKey low endpoint (inclusive) of the tailMap
287	dl	1.1	* @return a view of the portion of this map whose keys are greater
288	jsr166	1.11	* than or equal to {@code fromKey}
289			* @throws ClassCastException if {@code fromKey} is not compatible
290	dl	1.1	* with this map's comparator (or, if the map has no comparator,
291	jsr166	1.11	* if {@code fromKey} does not implement {@code Comparable})
292			* @throws NullPointerException if {@code fromKey} is {@code null}
293			* and this map does not support {@code null} keys
294	dl	1.1	*/
295	jsr166	1.8	public NavigableMap<K,V> tailMap(K fromKey);
296	dl	1.1	}