.of(LONG_MANY_VALUES_MEAN);
    assertThat(longManyValuesAccumulatorByAddAllVarargs.mean())
        .isWithin(ALLOWED_ERROR * LONG_MANY_VALUES_MEAN)
        .of(LONG_MANY_VALUES_MEAN);
  }

  public void testSum() {
    assertThat(emptyAccumulator.sum()).isEqualTo(0.0);
    assertThat(emptyAccumulatorByAddAllEmptyIterable.sum()).isEqualTo(0.0);
    assertThat(emptyAccumulatorByAddAllEmptyStats.sum()).isEqualTo(0.0);

    assertThat(Enums.getIfPresent(TestEnum.class, "HONDA")).isPresent();
    assertThat(Enums.getIfPresent(TestEnum.class, "POODLE")).isPresent();

    assertThat(Enums.getIfPresent(TestEnum.class, "CHEETO")).hasValue(TestEnum.CHEETO);
    assertThat(Enums.getIfPresent(TestEnum.class, "HONDA")).hasValue(TestEnum.HONDA);
    assertThat(Enums.getIfPresent(TestEnum.class, "POODLE")).hasValue(TestEnum.POODLE);
  }

      assertEquals(0, table.size());
      assertFalse(table.containsRow("foo"));
    } else {
      assertThrows(UnsupportedOperationException.class, () -> table.clear());
    }
  }

  public void testPut() {
    assertThat(table.put("foo", 1, cellValue('a'))).isNull();
    assertThat(table.put("bar", 1, cellValue('b'))).isNull();
    assertThat(table.put("foo", 3, cellValue('c'))).isNull();

      assertEquals(0, table.size());
      assertFalse(table.containsRow("foo"));
    } else {
      assertThrows(UnsupportedOperationException.class, () -> table.clear());
    }
  }

  public void testPut() {
    assertThat(table.put("foo", 1, cellValue('a'))).isNull();
    assertThat(table.put("bar", 1, cellValue('b'))).isNull();
    assertThat(table.put("foo", 3, cellValue('c'))).isNull();