code: def IsLoopConstantEnter(op):
      """Return true iff op is a loop invariant."""
      return IsLoopEnter(op) and op.get_attr("is_constant")
  
imports: import os
  import traceback
  from tensorflow.python import tf2
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 16 for calling a global function with example usage: IsLoopConstantEnter(op) and returns: unknown