class_docstr: A non-blocking TCP connection factory.
  
  .. versionchanged:: 4.1
     The ``io_loop`` argument is deprecated.
code: def close(self):
      if self._own_resolver:
          self.resolver.close()
  
imports: from __future__ import absolute_import, division, print_function
  import functools
  import socket
  from tornado.concurrent import Future
  from tornado.ioloop import IOLoop
  from tornado.iostream import IOStream
  from tornado import gen
  from tornado.netutil import Resolver
  from tornado.platform.auto import set_close_exec
label_desc: Use image node_id 2 for calling the TCPClient obj's underlying member method code with example usage: obj.close() without return types