assertNull(groovyEngine.evaluate("return nonExistentVariable", params));
    }

    /**
     * Test that syntax errors return null
     */
    @Test
    public void test_evaluate_syntaxErrorReturnsNull() {
        final Map<String, Object> params = new HashMap<>();
        assertNull(groovyEngine.evaluate("this is not valid groovy code {{{", params));
    }

    /**