code: def is_tensor_list(t):
      # TODO(mdan): This is just a heuristic.
      # With TF lacking support for templated types, this is unfortunately the
      # closest we can get right now. A dedicated op ought to be possible to
      # construct.
      return (
          tensor_util.is_tf_type(t)
          and t.dtype == dtypes.variant
          and not t.shape.ndims
      )
  
file_path: tensorflow-upstream/tensorflow/python/autograph/utils/tensors.py
imports: from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import sparse_tensor
  from tensorflow.python.framework import tensor_util
  from tensorflow.python.ops import tensor_array_ops
label_desc: Use image node_id 3 for calling a global function with example usage: is_tensor_list(t) and returns: unknown