code: def _expand_ref_point(ref_point: Tensor, batch_shape: Size) -> Tensor:
      r"""Expand reference point to the proper batch_shape.
  
      Args:
          ref_point: A `(batch_shape) x m`-dim tensor containing the reference
              point.
          batch_shape: The batch shape.
  
      Returns:
          A `batch_shape x m`-dim tensor containing the expanded reference point
      """
      if ref_point.shape[:-1] != batch_shape:
          if ref_point.ndim > 1:
              raise BotorchTensorDimensionError(
                  "Expected ref_point to be a `batch_shape x m` or `m`-dim tensor, "
                  f"but got {ref_point.shape}."
              )
          ref_point = ref_point.view(
              *(1 for _ in batch_shape), ref_point.shape[-1]
          ).expand(batch_shape + ref_point.shape[-1:])
      return ref_point
  
file_path: botorch/botorch/utils/multi_objective/box_decompositions/utils.py
imports: from typing import Optional, Tuple
  import torch
  from botorch.exceptions.errors import BotorchTensorDimensionError, UnsupportedError
  from botorch.utils.multi_objective.pareto import is_non_dominated
  from torch import Size, Tensor
label_desc: Use image node_id 1 for calling a global function with example usage: _expand_ref_point(ref_point, batch_shape) and returns: ref_point