Is the element NIL, and is that okay?
        Parameters:
            elt -- the DOM element being parsed
            ps -- the ParsedSoap object.

def nilled(self, elt, ps):
        '''Is the element NIL, and is that okay?
        Parameters:
            elt -- the DOM element being parsed
            ps -- the ParsedSoap object.
        '''
        if _find_nil(elt) not in [ "true",  "1"]: return False
        if self.nillable is False:
            raise EvaluateException('Non-nillable element is NIL',
                    ps.Backtrace(elt))
        return True