def Subscribe(self, request_iterator, context):
context.set_code(grpc.StatusCode.UNIMPLEMENTED)<EOL>context.set_details('<STR_LIT>')<EOL>raise NotImplementedError('<STR_LIT>')<EOL>
Subscribe allows a client to request the target to send it values
        of particular paths within the data tree. These values may be streamed
        at a particular cadence (STREAM), sent one off on a long-lived channel
        (POLL), or sent as a one-off retrieval (ONCE).
        Reference: gNMI Specification Section 3.5