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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 get_connection_id_by_endpoint(self, endpoint):
 """Returns the connection id associated with a publically reachable endpoint or raises KeyError if the endpoint is not found. Args: endpoint (str):
 A zmq-style uri which identifies a publically reachable endpoint. """

        with self._connections_lock:
            for connection_id in self._connections:
                connection_info = self._connections[connection_id]
                if connection_info.uri == endpoint:
                    return connection_id
            raise KeyError()