* <p>Some algorithms that operate on a {@code PredecessorsFunction} may produce undesired results
   * if the returned {@link Iterable} contains duplicate elements. Implementations of such
   * algorithms should document their behavior in the presence of duplicates.
   *
   * <p>The elements of the returned {@code Iterable} must each be:
   *
   * <ul>
   *   <li>Non-null
   *   <li>Usable as {@code Map} keys (see the Guava User Guide's section on <a

 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},

 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},

 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},

   * {@code put()} or {@code putAll()}, or {@code setValue()} on its entries.
   *
   * <p>In contrast, the maps returned by {@code rowMap().get()} have the same behavior as those
   * returned by {@link #row}. Those maps may support {@code setValue()}, {@code put()}, and {@code
   * putAll()}.
   *
   * @return a map view from each row key to a secondary map from column keys to values

   * It's unclear whether nulls were to be permitted or forbidden, but presumably the eventual fix
   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in set(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getSetNullSupportedMethod() {

   * <p>Some algorithms that operate on a {@code PredecessorsFunction} may produce undesired results
   * if the returned {@link Iterable} contains duplicate elements. Implementations of such
   * algorithms should document their behavior in the presence of duplicates.
   *
   * <p>The elements of the returned {@code Iterable} must each be:
   *
   * <ul>
   *   <li>Non-null
   *   <li>Usable as {@code Map} keys (see the Guava User Guide's section on <a

 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},

 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},

 * Table} interface.
 *
 * <p>Null keys and values are not supported.
 *
 * <p>See the {@link StandardTable} superclass for more information about the behavior of this
 * class.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
class StandardRowSortedTable<R, C, V> extends StandardTable<R, C, V>
    implements RowSortedTable<R, C, V> {