@Override
    public boolean hasVariable(String name) {
        if (variables.containsKey(name)) {
            return true;
        }
        if (parent != null) {
            return parent.hasVariable(name);
        }
        return false;
    }
@Test
    public void testHasVariable() {
        ProcessContextImpl context = new ProcessContextImpl();
        Assertions.assertFalse(context.hasVariable("key"));
    }