code: def cork(self):
          
          s = mitogen.core.b('CORK') * ((128 // 4) * 1024)
          self._rsocks = []
  
          # Pools must be paused first, as existing work may require the
          # participation of a broker in order to complete.
          for pool in self.pools:
              if not pool.closed:
                  for x in range(pool.size):
                      self._cork_one(s, pool)
  
          for broker in self.brokers:
              if broker._alive:
                  self._cork_one(s, broker)
  
          # Pause until we can detect every thread has entered write().
          for rsock in self._rsocks:
              self._verify_one(rsock)
docs: Arrange for any associated brokers and pools to be paused with no locks
          held. This will not return until each thread acknowledges it has ceased
          execution.