### Question:
BoxedExpressionHelper { public Expression getExpression(final Node<View, Edge> node) { return getHasExpression(node).getExpression(); }  Optional<HasExpression> getOptionalHasExpression(final Node<View, Edge> node); Optional<Expression> getOptionalExpression(final Node<View, Edge> node); Expression getExpression(final Node<View, Edge> node); HasExpression getHasExpression(final Node<View, Edge> node);  }### Answer:
@Test public void testGetExpression() { final View content = mock(View.class); final Decision decision = mock(Decision.class); final Expression expectedExpression = mock(Expression.class); when(node.getContent()).thenReturn(content); when(content.getDefinition()).thenReturn(decision); when(decision.getExpression()).thenReturn(expectedExpression); final Expression actualExpression = helper.getExpression(node); assertEquals(expectedExpression, actualExpression); }