class_docstr: Abstract base class for acquisition functions.
  
  Please note that if your acquisition requires a backwards call,
  you will need to wrap the backwards call inside of an enable_grad
  context to be able to optimize the acquisition. See #1164.
  
  :meta private:
docstr: Informs the acquisition function about pending design points.
  
  Args:
      X_pending: `n x d` Tensor with `n` `d`-dim design points that have
          been submitted for evaluation but have not yet been evaluated.
docstr_tok: ["Informs","the","acquisition","function","about","pending","design","points",".","Args",":","X_pending",":","`","n","x","d","`","Tensor","with","`","n","`","`","d","`","-dim","design","points","that","have","been","submitted","for","evaluation","but","have","not","yet","been","evaluated","."]
code: def set_X_pending(self, X_pending: Optional[Tensor] = None) -> None:
      r"""Informs the acquisition function about pending design points.
  
      Args:
          X_pending: `n x d` Tensor with `n` `d`-dim design points that have
              been submitted for evaluation but have not yet been evaluated.
      """
      if X_pending is not None:
          if X_pending.requires_grad:
              warnings.warn(
                  "Pending points require a gradient but the acquisition function"
                  " will not provide a gradient to these points.",
                  BotorchWarning,
              )
          self.X_pending = X_pending.detach().clone()
      else:
          self.X_pending = X_pending
  
imports: from __future__ import annotations
  import warnings
  from abc import ABC, abstractmethod
  from typing import Optional
  import torch
  from botorch.exceptions import BotorchWarning
  from botorch.models.model import Model, ModelDict
  from botorch.posteriors.posterior import Posterior
  from botorch.sampling.base import MCSampler
  from botorch.sampling.get_sampler import get_sampler
  from torch import Tensor
  from torch.nn import Module
label_desc: Use image node_id 2 for calling the AcquisitionFunction obj's underlying member method code with example usage: obj.set_X_pending(X_pending) without return types