@Test
 public void createCoalesceExpression_ObjectAndStringOperands_ReturnClassIsString() {
   Class<?> expectedClass = Object.class;
   Object left = new Object();
   Object right = "1";
   Expression e = coalesce(left, right);
   assertThat(e.getResultClass(), is(assignableTo(expectedClass)));
 }
 @Test
 public void createCoalesceExpression_NullAndObjectOperands_ReturnClassIsString() {
   Class<?> expectedClass = String.class;
   Object left = null;
   Object right = new String();
   Expression e = coalesce(left, right);
   assertThat(e.getResultClass(), is(assignableTo(expectedClass)));
 }