def _reset_metadata_tracking(self, fields=None):
        if fields is None or 'system_metadata' in fields:
            self._orig_system_metadata = (dict(self.system_metadata) if
                                          'system_metadata' in self else {})
        if fields is None or 'metadata' in fields:
            self._orig_metadata = (dict(self.metadata) if
                                   'metadata' in self else {})
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/objects/instance.py/Instance._reset_metadata_tracking/original