@Test
void mapBooleanToDouble() {

    final ToBoolean<Boolean> toBoolean = bool -> bool;
    final ToDoubleMapper<Boolean, ToBoolean<Boolean>, BooleanToDoubleFunction> toDoubleMapper =
            (ToDoubleMapper<Boolean, ToBoolean<Boolean>, BooleanToDoubleFunction>)
                    MapperUtil.mapBooleanToDouble(toBoolean, bool -> 1);
    assertEquals(MapperType.BOOLEAN_TO_DOUBLE, toDoubleMapper.mapperType());
}