un-wrapped execution, can raise excepetion

        :return: Execution result
        :rtype: kser.result.Result

def unsafe_execute(self, result=None):
        """ un-wrapped execution, can raise excepetion

        :return: Execution result
        :rtype: kser.result.Result
        """
        if result:
            self.result += result

        self._prerun()
        return self._onsuccess(self._postrun(self._run()))