code: def release(self, connection):
          "Releases the connection back to the pool"
          self._checkpid()
          if connection.pid != self.pid:
              return
          self._in_use_connections.remove(connection)
          # discard connection with unread response
          if connection.awaiting_response:
              connection.disconnect()
              self._created_connections -= 1
          else:
              self._available_connections.append(connectionf release(self, connection):
          "Releases the connection back to the pool"
          self._checkpid()
          if connection.pid != self.pid:
              return
          self._in_use_connections.remove(connection)
          # discard connection with unread response
          if connection.awaiting_response:
              connection.disconnect()
              self._created_connections -= 1
          else:
              self._available_connections.append(connection)
docs: Releases the connection back to the pool