Table<String, Integer, Character> table = transpose(original);
    table.clear();
    populate(table, data);
    return table;
  }

  public void testTransposeTransposed() {
    Table<Integer, String, Character> original = HashBasedTable.create();
    assertThat(transpose(transpose(original))).isSameInstanceAs(original);
  }

  public void testPutOriginalModifiesTranspose() {