} catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testEntrySet() {
    Map<K, V> map;
    try {
      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }
    assertInvariants(map);

    Set<Entry<K, V>> entrySet = map.entrySet();
    K unmappedKey;
    V unmappedValue;

      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testEntrySet() {
    Map<K, V> map;
    try {
      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }
    assertInvariants(map);

    Set<Entry<K, V>> entrySet = map.entrySet();
    K unmappedKey;
    V unmappedValue;

        assertEquals(initialSize - 1, map.size());
      } else {
        assertThrows(UnsupportedOperationException.class, () -> map.remove(keyToRemove));
      }
      assertInvariants(map);
    }
  }

  abstract static class RowMapTests extends MapMapTests {
    RowMapTests(
        boolean allowsNullValues,
        boolean supportsRemove,
        boolean supportsClear,

        assertEquals(initialSize - 1, map.size());
      } else {
        assertThrows(UnsupportedOperationException.class, () -> map.remove(keyToRemove));
      }
      assertInvariants(map);
    }
  }

  abstract static class RowMapTests extends MapMapTests {
    RowMapTests(
        boolean allowsNullValues,
        boolean supportsRemove,
        boolean supportsClear,