code: def get_node(service_name, host_name):
      
      return common_pb2.Node(
          identifier=common_pb2.ProcessIdentifier(
              host_name=socket.gethostname() if host_name is None
              else host_name,
              pid=os.getpid(),
              start_timestamp=proto_ts_from_datetime(
                  datetime.datetime.utcnow())),
          library_info=common_pb2.LibraryInfo(
              language=common_pb2.LibraryInfo.Language.Value('PYTHON'),
              exporter_version=EXPORTER_VERSION,
              core_library_version=opencensus_version),
          service_info=common_pb2.ServiceInfo(name=service_name))
docs: Generates Node message from params and system information.