### Question:
DecisionRule extends DMNElement implements HasTypeRefs { @Override public List<HasTypeRef> getHasTypeRefs() { return new ArrayList<>(getFlatHasTypeRefs(getOutputEntry())); } DecisionRule();  DecisionRule(final Id id,
                        final Description description,
                        final List<UnaryTests> inputEntry,
                        final List<LiteralExpression> outputEntry); DecisionRule copy(); List<RuleAnnotationClauseText> getAnnotationEntry(); List<UnaryTests> getInputEntry(); List<LiteralExpression> getOutputEntry(); @Override List<HasTypeRef> getHasTypeRefs(); @Override boolean equals(final Object o); @Override int hashCode();  }### Answer:
@Test public void testGetHasTypeRefs() { final LiteralExpression literalExpression1 = mock(LiteralExpression.class); final LiteralExpression literalExpression2 = mock(LiteralExpression.class); final List<LiteralExpression> outputEntry = asList(literalExpression1, literalExpression2); doReturn(outputEntry).when(decisionRule).getOutputEntry(); when(literalExpression1.getHasTypeRefs()).thenReturn(asList(literalExpression1)); when(literalExpression2.getHasTypeRefs()).thenReturn(asList(literalExpression2)); final List<HasTypeRef> actualHasTypeRefs = decisionRule.getHasTypeRefs(); final List<HasTypeRef> expectedHasTypeRefs = asList(literalExpression1, literalExpression2); assertEquals(expectedHasTypeRefs, actualHasTypeRefs); }