class_docstr: Hides a tensor from the autograd engine by a :class:`Portal`.
class_docstr_tok: ["Hides","a","tensor","from","the","autograd","engine","by","a",":","class",":","`","Portal","`","."]
code: def forward(
      ctx: Context,
      portal: Portal,
      # This tensor must be retrieved by portal.use_tensor().
      tensor: Tensor,
  ) -> Tensor:
      ctx.portal = portal
  
      phony = get_phony(tensor.device, requires_grad=False)
      return phony.detach()
  
imports: from typing import Any, List, Optional, Tuple
  import torch
  from torch import Tensor
  from .None import Namespace
  from ..copy import Context
  from ..copy import Copy
  from ..phony import get_phony
  from ..stream import AbstractStream, get_device
label_desc: Use image node_id 1 for calling the PortalBlue obj's underlying member method code with example usage: obj.forward(ctx, portal, tensor) and returns: phony