SortedMap<String, Integer> createUnfiltered() {
    return Maps.newTreeMap();
  }

  public void testFirstAndLastKeyFilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("apple", 2);
    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);

  SortedMap<String, Integer> createUnfiltered() {
    return Maps.newTreeMap();
  }

  public void testFirstAndLastKeyFilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("apple", 2);
    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);

  }

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

  }

  @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();
  }

  }

  @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();
  }

  }

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