code: def IsLoopMerge(op):
      """Return true if `op` is the Merge for a while loop."""
      if IsMerge(op):
          ctxt = (
              op._get_control_flow_context()
          )  # pylint: disable=protected-access
          return (
              ctxt is not None
              and ctxt.IsWhileContext()
              and not IsCondMerge(op)
          )
      return False
  
imports: import os
  import traceback
  from tensorflow.python import tf2
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 15 for calling a global function with example usage: IsLoopMerge(op) and returns: False, unknown