the "RRef" will appropriately raise errors. However, it is
     possible that the user application will use the "RRef" before the
     errors are handled. In this case, errors may not be raised as
     they have not yet been handled.
Example:
  Make sure that ``MASTER_ADDR`` and ``MASTER_PORT`` are set properly
  on both workers. Refer to :meth:`~torch.distributed.init_process_group`
  API for more details. For example,

  export MASTER_ADDR=localhost
  export MASTER_PORT=5678

  Then run the following code in two different processes:

  >>> # On worker 0:
  >>> import torch
  >>> import torch.distributed.rpc as rpc
  >>> rpc.init_rpc("worker0", rank=0, world_size=2)
  >>> rref1 = rpc.remote("worker1", torch.add, args=(torch.ones(2), 3))
  >>> rref2 = rpc.remote("worker1", torch.add, args=(torch.ones(2), 1))
  >>> x = rref1.to_here() + rref2.to_here()
  >>> rpc.shutdown()

  >>> # On worker 1:
  >>> import torch.distributed.rpc as rpc
