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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _process_err(self, err=None):
 """ Stores the last received error from the server and dispatches the error callback. """

        self.stats['errors_received'] += 1

        if err == "'Authorization Violation'":
            self._err = ErrAuthorization
        elif err == "'Slow Consumer'":
            self._err = ErrSlowConsumer
        elif err == "'Stale Connection'":
            self._err = ErrStaleConnection
        else:
            self._err = Exception(err)

        if self._error_cb is not None:
            self._error_cb(err)