@Test
public void test_boolean_or_null() {

  FunctionExpression or =
      dsl.or(DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD, BOOLEAN));
  assertEquals(BOOLEAN, or.type());
  assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
  or = dsl.or(DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD, BOOLEAN), DSL.literal(LITERAL_TRUE));
  assertEquals(BOOLEAN, or.type());
  assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
  or = dsl.or(DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD, BOOLEAN));
  assertEquals(BOOLEAN, or.type());
  assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
  or = dsl.or(DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD, BOOLEAN), DSL.literal(LITERAL_FALSE));
  assertEquals(BOOLEAN, or.type());
  assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
}