assertTrue(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("b", null)));
    assertTrue(
        entries.contains(Maps.<@Nullable String, @Nullable Boolean>immutableEntry(null, null)));

    assertFalse(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("c", null)));
    assertFalse(entries.contains(Maps.<@Nullable String, Boolean>immutableEntry(null, true)));
  }

    assertEquals(ImmutableSortedMap.of(2, 0), Maps.subMap(map, Range.open(0, 4)));
    assertEquals(ImmutableSortedMap.of(4, 0), Maps.subMap(map, Range.open(2, 6)));
    assertEquals(ImmutableSortedMap.of(4, 0, 6, 0), Maps.subMap(map, Range.open(3, 7)));
    assertEquals(empty, Maps.subMap(map, Range.open(20, 30)));

    assertEquals(map, Maps.subMap(map, Range.openClosed(0, 12)));

   * to this implementation.
   *
   * @since 7.0
   */
  protected void standardPutAll(Map<? extends K, ? extends V> map) {
    Maps.putAllImpl(this, map);
  }

  /**
   * A sensible, albeit inefficient, definition of {@link #remove} in terms of the {@code iterator}

                    putEntries(map, entries);
                    map.putAll(ENTRIES_TO_FILTER);
                    map = Maps.filterEntries(map, FILTER_ENTRIES_1);
                    return Maps.filterEntries(map, FILTER_ENTRIES_2);
                  }
                })
            .named("Maps.filterEntries[Maps.filterEntries[Map, Predicate], Predicate]")
            .withFeatures(
                MapFeature.ALLOWS_NULL_KEYS,

    assertEquals(ImmutableSortedMap.of(2, 0), Maps.subMap(map, Range.open(0, 4)));
    assertEquals(ImmutableSortedMap.of(4, 0), Maps.subMap(map, Range.open(2, 6)));
    assertEquals(ImmutableSortedMap.of(4, 0, 6, 0), Maps.subMap(map, Range.open(3, 7)));
    assertEquals(empty, Maps.subMap(map, Range.open(20, 30)));

    assertEquals(map, Maps.subMap(map, Range.openClosed(0, 12)));

                    putEntries(map, entries);
                    map.putAll(ENTRIES_TO_FILTER);
                    map = Maps.filterEntries(map, FILTER_ENTRIES_1);
                    return Maps.filterEntries(map, FILTER_ENTRIES_2);
                  }
                })
            .named("Maps.filterEntries[Maps.filterEntries[Map, Predicate], Predicate]")
            .withFeatures(
                MapFeature.ALLOWS_NULL_KEYS,

/**
 * An object representing the differences between two maps.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@DoNotMock("Use Maps.difference")
@GwtCompatible
public interface MapDifference<K extends @Nullable Object, V extends @Nullable Object> {
  /**
   * Returns {@code true} if there are no differences between the two maps; that is, if the maps are
   * equal.
   */
  boolean areEqual();

  /**

	}

	ns := NamingStrategy{}
	for key, value := range maps {
		if ns.toDBName(key) != value {
			t.Errorf("%v toName should equal %v, but got %v", key, value, ns.toDBName(key))
		}
	}

	maps = map[string]string{
		"x":                              "X",
		"user_restrictions":              "UserRestriction",

          .put(ImmutableMap.class, ImmutableMap.of())
          .put(SortedMap.class, ImmutableSortedMap.of())
          .put(ImmutableSortedMap.class, ImmutableSortedMap.of())
          .put(NavigableMap.class, Maps.unmodifiableNavigableMap(Maps.newTreeMap()))
          .put(Multimap.class, ImmutableMultimap.of())
          .put(ImmutableMultimap.class, ImmutableMultimap.of())
          .put(ListMultimap.class, ImmutableListMultimap.of())

  abstract Map<String, Integer> createUnfiltered();

  public void testFilteredKeysIllegalPut() {
    Map<String, Integer> unfiltered = createUnfiltered();
    Map<String, Integer> filtered = Maps.filterKeys(unfiltered, NOT_LENGTH_3);
    filtered.put("a", 1);
    filtered.put("b", 2);
    assertEquals(ImmutableMap.of("a", 1, "b", 2), filtered);