qiskit/circuit/instruction.py
def params(self):
        """return instruction params"""
        # if params already defined don't attempt to get them from definition
        if self._definition and not self._params:
            self._params = []
            for sub_instr, _, _ in self._definition:
                self._params.extend(sub_instr.params)  # recursive call
            return self._params
        else:
            return self._params
def params(self):
        """return instruction params"""
        # if params already defined don't attempt to get them from definition
        if self._definition and not self._params:
            self._params = []
            for sub_instr, _, _ in self._definition:
                self._params.extend(sub_instr.params)  # recursive call
            return self._params
        else:
            return self._params
return instruction params