code: def socket(self, socket_type):
      s = self.context.socket(socket_type)
      self.sockets.append(s)
      return s
  
imports: import sys
  import time
  from threading import Thread
  from unittest import TestCase
  from pytest import mark
  import zmq
  from zmq.utils import jsonapi
label_desc: Use image node_id 2 for calling the BaseZMQTestCase obj's underlying member method code with example usage: obj.socket(socket_type) and returns: s