}

  /** Creates an empty {@code HashBasedTable}. */
  public static <R, C, V> HashBasedTable<R, C, V> create() {
    return new HashBasedTable<>(new LinkedHashMap<R, Map<C, V>>(), new Factory<C, V>(0));
  }

  /**
   * Creates an empty {@code HashBasedTable} with the specified map sizes.
   *
   * @param expectedRows the expected number of distinct row keys

  }

  /** Creates an empty {@code HashBasedTable}. */
  public static <R, C, V> HashBasedTable<R, C, V> create() {
    return new HashBasedTable<>(new LinkedHashMap<R, Map<C, V>>(), new Factory<C, V>(0));
  }

  /**
   * Creates an empty {@code HashBasedTable} with the specified map sizes.
   *
   * @param expectedRows the expected number of distinct row keys

                  protected Set<String> create(String[] elements) {
                    Table<String, Integer, Character> table = HashBasedTable.create();
                    populateForRowKeySet(table, elements);
                    return table.rowKeySet();
                  }
                })
            .named("HashBasedTable.rowKeySet")
            .withFeatures(COLLECTION_FEATURES_REMOVE)

  }

  public void testEqualsObject() {
    new EqualsTester()
        .addEqualityGroup(testTable, HashBasedTable.create(testTable))
        .addEqualityGroup(ImmutableTable.of(), HashBasedTable.create())
        .addEqualityGroup(HashBasedTable.create(ImmutableTable.of('A', 2, "")))
        .testEquals();
  }

  @GwtIncompatible // ArrayTable
  public void testEqualsObjectNullValues() {

    assertEquals(0, INSTANCE.hashCode());
  }

  public void testEqualsObject() {
    Table<Character, Integer, String> nonEmptyTable = HashBasedTable.create();
    nonEmptyTable.put('A', 1, "blah");

    new EqualsTester()
        .addEqualityGroup(INSTANCE, HashBasedTable.create(), TreeBasedTable.create())
        .addEqualityGroup(nonEmptyTable)
        .testEquals();
  }

  @GwtIncompatible // ArrayTable

          return input == null ? null : input.charAt(0);
        }
      };

  @Override
  protected Table<String, Integer, Character> create(@Nullable Object... data) {
    Table<String, Integer, String> table = HashBasedTable.create();
    checkArgument(data.length % 3 == 0);
    for (int i = 0; i < data.length; i += 3) {
      String value = (data[i + 2] == null) ? null : (data[i + 2] + "transformed");

   * analogous operation with swapped rows and columns. For example, in a {@link HashBasedTable}
   * instance, {@code rowKeySet().iterator()} supports {@code remove()} but {@code
   * columnKeySet().iterator()} doesn't. With a transposed {@link HashBasedTable}, it's the other
   * way around.
   */

    }
  }

  public void testPutAllTable() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    Table<String, Integer, @NonNull C> other = HashBasedTable.create();
    other.put("foo", 1, cellValue('d'));
    other.put("bar", 2, cellValue('e'));
    other.put("cat", 2, cellValue('f'));
    table.putAll(other);
    assertEquals((Character) 'd', table.get("foo", 1));

 * UnsupportedOperationException}.
 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableTable}
 *   <li>{@link HashBasedTable}
 *   <li>{@link TreeBasedTable}
 *   <li>{@link ArrayTable}
 *   <li>{@link Tables#newCustomTable Tables.newCustomTable}
 * </ul>
 *
 * <p>See the Guava User Guide article on <a href=

@NullUnmarked
public class SynchronizedTableTest extends AbstractTableTest<Character> {
  private static final class TestTable<R, C, V> implements Table<R, C, V>, Serializable {
    private final Table<R, C, V> delegate = HashBasedTable.create();
    private final Object mutex = new Object[0]; // something Serializable

    @Override
    public String toString() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.toString();
    }