class_docstr: A file like object that publishes the stream to a 0MQ PUB socket.
  
  Output is handed off to an IO Thread
class_docstr_tok: ["A","file","like","object","that","publishes","the","stream","to","a","0MQ","PUB","socket",".","Output","is","handed","off","to","an","IO","Thread"]
docstr: clear the current buffer and return the current buffer data.
  
  This should only be called in the IO thread.
code: def _flush_buffer(self):
      """clear the current buffer and return the current buffer data.
  
      This should only be called in the IO thread.
      """
      data = ""
      if self._buffer is not None:
          buf = self._buffer
          self._new_buffer()
          data = buf.getvalue()
          buf.close()
      return data
  
imports: from __future__ import print_function
  import atexit
  from binascii import b2a_hex
  from collections import deque
  import os
  import sys
  import threading
  import warnings
  from io import StringIO, TextIOBase
  import zmq
  from zmq.eventloop.ioloop import IOLoop
  from zmq.eventloop.zmqstream import ZMQStream
  from jupyter_client.session import extract_header
  from ipython_genutils import py3compat
  from ipython_genutils.py3compat import unicode_type
label_desc: Use image node_id 12 for calling the OutStream obj's underlying member method code with example usage: obj._flush_buffer() and returns: data