torch.Tensor.copy_
Tensor.copy_(src, non_blocking=False) -> Tensor
Copies the elements from "src" into "self" tensor and returns
   "self".
The "src" tensor must be broadcastable with the "self" tensor. It
   may be of a different data type or reside on a different device.
Parameters:
      * src (Tensor) -- the source tensor to copy from
  * **non_blocking** (*bool*) -- if "True" and this copy is
    between CPU and GPU, the copy may occur asynchronously with
    respect to the host. For other cases, this argument has no
    effect.
