def _check_dangling_params(self, out_stream=sys.stdout):
        """ Check for parameters that are not connected to a source/unknown.
        this includes ALL dangling params, both promoted and unpromoted.
        """
        to_prom_name = self.root._sysdata.to_prom_name

        dangling_params = sorted(set([
            to_prom_name[p] for p, m in iteritems(self.root._params_dict)
            if self.root.connections not in p
        ]))
        if dangling_params:
            print("\nThe following parameters have no associated unknowns:",
                  file=out_stream)
            for d in dangling_params:
                print(d, file=out_stream)

        return dangling_params
dataset/ETHPy150Open OpenMDAO/OpenMDAO/openmdao/core/problem.py/Problem._check_dangling_params/swapped operands of `not in`