class_docstr: Client to register and await node reservations.
  
  Args:
    :server_addr: a tuple of (host, port) pointing to the Server.
docstr: Poll until all reservations completed, then return cluster_info.
docstr_tok: ["Poll","until","all","reservations","completed",",","then","return","cluster_info","."]
code: def await_reservations(self):
      """Poll until all reservations completed, then return cluster_info."""
      done = False
      while not done:
          done = self._request("QUERY")
          time.sleep(1)
      return self.get_reservations()
  
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 6 for calling the Client obj's underlying member method code with example usage: obj.await_reservations() and returns: self