Entry<K, V> firstEntry = iterator.next();
    Entry<K, V> secondEntry = iterator.next();
    K key = secondEntry.getKey();
    SortedMap<K, V> subMap = map.tailMap(key);
    V value = getValueNotInPopulatedMap();
    subMap.put(key, value);
    assertEquals(secondEntry.getValue(), value);
    assertEquals(map.get(key), value);
    assertThrows(IllegalArgumentException.class, () -> subMap.put(firstEntry.getKey(), value));

          supportsIteratorRemove);
    }

    @Override
    protected String getKeyNotInPopulatedMap() {
      return "four";
    }

    @Override
    protected Integer getValueNotInPopulatedMap() {
      return 4;
    }
  }

  abstract static class RowTests extends MapTests {
    RowTests(
        boolean allowsNullValues,
        boolean supportsPut,
        boolean supportsRemove,

          supportsIteratorRemove);
    }

    @Override
    protected String getKeyNotInPopulatedMap() {
      return "four";
    }

    @Override
    protected Integer getValueNotInPopulatedMap() {
      return 4;
    }
  }

  abstract static class RowTests extends MapTests {
    RowTests(
        boolean allowsNullValues,
        boolean supportsPut,
        boolean supportsRemove,

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

  @Override
  protected String getKeyNotInPopulatedMap() throws UnsupportedOperationException {
    return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {
    assertEquals(expected, map);

  }

  @Override
  protected String getKeyNotInPopulatedMap() throws UnsupportedOperationException {
    return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {