}

  @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 unmodifiableTable(table).column('a');
  }

  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    table.put('a', "one", 2);
    table.put('a', "two", 4);
    table.put('a', "three", 6);
    table.put('b', "four", 8);
    return transformValues(table, TableCollectionTest.DIVIDE_BY_2).row('a');
  }

    super(false, true, true, true, true);
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    NavigableMap<String, Integer> map = new SafeTreeMap<>();
    map.put("one", 1);
    map.put("two", 2);
    map.put("three", 3);
    return SerializableTester.reserialize(map);
  }

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() throws UnsupportedOperationException {

  }

  @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 unmodifiableRowSortedTable(table).row('a');
  }

  }

  @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 unmodifiableTable(table).column('a');
  }

    super(false, true, true, true, true);
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    NavigableMap<String, Integer> map = new SafeTreeMap<>();
    map.put("one", 1);
    map.put("two", 2);
    map.put("three", 3);
    return SerializableTester.reserialize(map);
  }

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() throws UnsupportedOperationException {

  }

  @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 unmodifiableRowSortedTable(table).row('a');
  }

  }

  @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 unmodifiableTable(table).row('a');
  }

// fields of this struct and deal with related migration.
type formatMetaV1 struct {
	// Version of the format config.
	Version string `json:"version"`
	// Format indicates the backend format type, supports two values 'xl' and 'fs'.
	Format string `json:"format"`
	// ID is the identifier for the minio deployment
	ID string `json:"id"`

  public void add(double x, double y) {
    // We extend the recursive expression for the one-variable case at Art of Computer Programming
    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.
    // We also define the sum of the products of the differences from the means