def __init__(self,<EOL>channel=None,<EOL>credentials=None,<EOL>address='<STR_LIT>'):
<EOL>if channel is not None and credentials is not None:<EOL><INDENT>raise ValueError(<EOL>'<STR_LIT>'<EOL>'<STR_LIT>', )<EOL><DEDENT>if channel is None:<EOL><INDENT>channel = self.create_channel(<EOL>address=address,<EOL>credentials=credentials,<EOL>)<EOL><DEDENT>self._stubs = {<EOL>'<STR_LIT>': agent_pb2_grpc.AgentsStub(channel),<EOL>}<EOL>self._operations_client = google.api_core.operations_v1.OperationsClient(<EOL>channel)<EOL>
Instantiate the transport class.

        Args:
            channel (grpc.Channel): A ``Channel`` instance through
                which to make calls. This argument is mutually exclusive
                with ``credentials``; providing both will raise an exception.
            credentials (google.auth.credentials.Credentials): The
                authorization credentials to attach to requests. These
                credentials identify this application to the service. If none
                are specified, the client will attempt to ascertain the
                credentials from the environment.
            address (str): The address where the service is hosted.