<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _copyValues(self, to, extra=None):
 """ Copies param values from this instance to another instance for params shared by them. :param to: the target instance :param extra: extra params to be copied :return: the target instance with param values copied """

        paramMap = self._paramMap.copy()
        if extra is not None:
            paramMap.update(extra)
        for param in self.params:
            # copy default params
            if param in self._defaultParamMap and to.hasParam(param.name):
                to._defaultParamMap[to.getParam(param.name)] = self._defaultParamMap[param]
            # copy explicitly set params
            if param in paramMap and to.hasParam(param.name):
                to._set(**{param.name: paramMap[param]})
        return to