code: def close(self):
          
          self.__auto_open = False
          self.__context_cond.acquire()
          try:
              while self.__context_refcount and self.__context_p:
                  self.__context_cond.wait()
              self._exit()
          finally:
              self.__context_cond.notifyAll()
              self.__context_cond.release()
docs: Close (destroy) this USB context, and all related instances.
  
          When this method has been called, methods on its instance will
          become mosty no-ops, returning None until explicitly re-opened
          (by calling open() or __enter__()).
  
          Note: "exit" is a deprecated alias of "close".