code: def ctx(self):
      if self._ctx is None or self._has_ctx == False:
          raise ValueError(
              "Context is not set yet, please call set_context() first"
          )
      return self._ctx
  
imports: import torch
  from typing import List, Literal
  import torch
  from fate.arch import Context
  from torch.nn.modules.module import T
label_desc: Use image node_id 8 for calling the _AggLayerBase obj's underlying member method code with example usage: obj.ctx() and returns: self