class_docstr: Client to register and await node reservations.
  
  Args:
    :server_addr: a tuple of (host, port) pointing to the Server.
docstr: Register ``reservation`` with server.
docstr_tok: ["Register","``","reservation","``","with","server","."]
code: def register(self, reservation):
      """Register ``reservation`` with server."""
      resp = self._request("REG", reservation)
      return resp
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import nested_scopes
  from __future__ import print_function
  import logging
  import os
  import pickle
  import select
  import socket
  import struct
  import sys
  import threading
  import time
  from .None import util
label_desc: Use image node_id 4 for calling the Client obj's underlying member method code with example usage: obj.register(reservation) and returns: resp