* first decrementing to zero, and then removing. putIfAbsent or replace could observe the
   * intermediate zero-state. Ways we could deal with this are:
   *
   * - Don't define any of the ConcurrentMap operations. This is the current state of affairs.
   *
   * - Define putIfAbsent and replace as treating zero and absent identically (as currently
   *   implemented below). This is a bit surprising with putIfAbsent, which really becomes

    }
    assertNull(map.get(unmappedKey));
  }

  public void testGetNull() {
    Map<K, V> map = makeEitherMap();
    if (allowsNullKeys) {
      if (allowsNullValues) {
        // TODO: decide what to test here.
      } else {
        assertEquals(map.containsKey(null), map.get(null) != null);
      }
    } else {
      try {
        map.get(null);
      } catch (NullPointerException optional) {

   * of their elements."
   *
   * </blockquote>
   */
  RESTRICTS_ELEMENTS,

  /**
   * Indicates that a collection has a well-defined ordering of its elements. The ordering may
   * depend on the element values, such as a {@link SortedSet}, or on the insertion ordering, such

  static final Integer N4 = 4;
  static final Integer N5 = 5;
  static final Integer NODE_NOT_IN_GRAPH = 1000;

  // TODO(user): Consider separating Strings that we've defined here to capture
  // identifiable substrings of expected error messages, from Strings that we've defined
  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.

    return requireLinks()[i];
  }

  private void setLink(int i, long value) {
    requireLinks()[i] = value;
  }

  /*
   * We don't define getPredecessor+getSuccessor and setPredecessor+setSuccessor here because
   * they're defined above -- including logic to add and subtract 1 to map between the values stored
   * in the predecessor/successor arrays and the indexes in the elements array that they identify.
   */

   * whose keys and values are the result of applying the provided mapping functions to the input
   * elements.
   *
   * <p>For streams with defined encounter order (as defined in the Ordering section of the {@link
   * java.util.stream} Javadoc), that order is preserved, but entries are <a
   * href="ImmutableMultimap.html#iteration">grouped by key</a>.
   *
   * <p>Example:
   *

   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *
   * <p>Note that this function is necessarily well-defined for any discrete type.
   *
   * @return the distance as described above, or {@link Long#MIN_VALUE} or {@link Long#MAX_VALUE} if
   *     the distance is too small or too large, respectively.
   */

  }

  @SuppressWarnings("rawtypes") // TreeBasedTable.create() is defined as such
  @Generates
  static <R extends Comparable, C extends Comparable, V>
      RowSortedTable<R, C, V> generateRowSortedTable(R row, C column, V value) {
    return generateTreeBasedTable(row, column, value);
  }

  @SuppressWarnings("rawtypes") // TreeBasedTable.create() is defined as such
  @Generates

@GwtIncompatible
@ElementTypesAreNonnullByDefault
public interface RangeMap<K extends Comparable, V> {
  /*
   * TODO(cpovirk): These docs sometimes say "map" and sometimes say "range map." Pick one, or at
   * least decide on a policy for when to use which.
   */

  /**
   * Returns the value associated with the specified key, or {@code null} if there is no such value.
   *

    }

    private static final long serialVersionUID = 0;
  }

  /**
   * Returns the composition of two functions. For {@code f: A->B} and {@code g: B->C}, composition
   * is defined as the function h such that {@code h(a) == g(f(a))} for each {@code a}.
   *
   * <p><b>Java 8+ users:</b> use {@code g.compose(f)} or (probably clearer) {@code f.andThen(g)}
   * instead.
   *