code: def inv_matmul(mat, right_tensor, left_tensor=None):
      warnings.warn(
          "gpytorch.inv_matmul is deprecated. Use gpytorch.solve instead.",
          DeprecationWarning,
      )
      return linear_operator.solve(right_tensor, left_tensor=None)
  
file_path: gpytorch/gpytorch/functions/__init__.py
imports: from __future__ import annotations
  import warnings
  from typing import Any
  import linear_operator
  import torch
  from ._log_normal_cdf import LogNormalCDF
  from .matern_covariance import MaternCovariance
  from .rbf_covariance import RBFCovariance
label_desc: Use image node_id 4 for calling a global function with example usage: inv_matmul(mat, right_tensor, left_tensor) and returns: linear_operator