code: def call(self, fn, *args, **kwargs):
          
          receiver = self.call_async(fn, *args, **kwargs)
          return receiver.get().unpickle(throw_dead=False)
docs: Like :meth:`call_async`, but block until the return value is available.
          Equivalent to::
  
              call_async(fn, *args, **kwargs).get().unpickle()
  
          :returns:
              The function's return value.
          :raises mitogen.core.CallError:
              An exception was raised in the remote context during execution.