code: def use_default_einsum():
      """Revert to the original einsum for the current backend"""
      global PREVIOUS_EINSUM
  
      if PREVIOUS_EINSUM is not None:
          tl.backend.BackendManager.register_backend_method(
              "einsum", PREVIOUS_EINSUM
          )
          PREVIOUS_EINSUM = None
  
imports: import tensorly
label_desc: Use image node_id 1 for calling a global function with example usage: use_default_einsum() without return types