return new SampleElements<>(
                        Tables.immutableCell("bar", 1, 'a'),
                        Tables.immutableCell("bar", 2, 'b'),
                        Tables.immutableCell("bar", 3, (Character) null),
                        Tables.immutableCell("bar", 4, 'b'),
                        Tables.immutableCell("bar", 5, 'b'));
                  }

                  @Override

public class RegularImmutableTableTest extends AbstractImmutableTableTest {
  private static final ImmutableSet<Cell<Character, Integer, String>> CELLS =
      ImmutableSet.of(
          Tables.immutableCell('a', 1, "foo"),
          Tables.immutableCell('b', 1, "bar"),
          Tables.immutableCell('a', 2, "baz"));

  private static final ImmutableSet<Character> ROW_SPACE = ImmutableSet.of('a', 'b');

                    return new SampleElements<>(
                        Tables.immutableCell("bar", 1, 'a'),
                        Tables.immutableCell("bar", 2, 'b'),
                        Tables.immutableCell("bar", 3, (Character) null),
                        Tables.immutableCell("bar", 4, 'b'),
                        Tables.immutableCell("bar", 5, 'b'));
                  }

                  @Override

    return Tables.immutableCell(
        checkNotNull(rowKey, "rowKey"),
        checkNotNull(columnKey, "columnKey"),
        checkNotNull(value, "value"));
  }

  /**
   * A builder for creating immutable table instances, especially {@code public static final} tables
   * ("constant tables"). Example:
   *
   * <pre>{@code

    return Tables.transformValues(original, FIRST_CHARACTER);
  }

  @Override
  protected Map<String, Map<Integer, Character>> makePopulatedMap() {
    Table<Integer, String, String> table = HashBasedTable.create();
    table.put(1, "foo", "apple");
    table.put(1, "bar", "banana");
    table.put(3, "foo", "cat");
    return Tables.transformValues(table, FIRST_CHARACTER).columnMap();
  }

    return Tables.unmodifiableTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    table.put('a', "one", 1);
    table.put('a', "two", 2);
    table.put('a', "three", 3);
    table.put('b', "four", 4);
    return Tables.unmodifiableTable(table).row('a');
  }

    return Tables.unmodifiableRowSortedTable(original);
  }

  @Override
  protected Map<String, Map<Integer, Character>> makePopulatedMap() {
    RowSortedTable<Integer, String, Character> table = TreeBasedTable.create();
    table.put(1, "foo", 'a');
    table.put(1, "bar", 'b');
    table.put(3, "foo", 'c');
    return Tables.unmodifiableRowSortedTable(table).columnMap();
  }

    return Tables.unmodifiableTable(original);
  }

  @Override
  protected Map<String, Map<Integer, Character>> makePopulatedMap() {
    Table<Integer, String, Character> table = HashBasedTable.create();
    table.put(1, "foo", 'a');
    table.put(1, "bar", 'b');
    table.put(3, "foo", 'c');
    return Tables.unmodifiableTable(table).columnMap();
  }

    return Tables.unmodifiableRowSortedTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    RowSortedTable<Character, String, Integer> table = TreeBasedTable.create();
    table.put('a', "one", 1);
    table.put('a', "two", 2);
    table.put('a', "three", 3);
    table.put('b', "four", 4);
    return Tables.unmodifiableRowSortedTable(table).row('a');
  }

    return Tables.unmodifiableTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<String, Character, Integer> table = HashBasedTable.create();
    table.put("one", 'a', 1);
    table.put("two", 'a', 2);
    table.put("three", 'a', 3);
    table.put("four", 'b', 4);
    return Tables.unmodifiableTable(table).column('a');
  }