code: def lexpand(A, *dimensions):
      """Expand tensor, adding new dimensions on left."""
      return A.expand(tuple(dimensions) + A.shape)
  
file_path: pyro/pyro/contrib/util.py
imports: import weakref
  from collections import OrderedDict
  import torch
  import pyro
label_desc: Use image node_id 6 for calling a global function with example usage: lexpand(A) and returns: A