code: def ldu(load_v, name):
      """Load variable operator that returns Undefined when failing to evaluate.
  
      Note: the name ("load or return undefined") is abbreviated to minimize
      the amount of clutter in generated code.
  
      This variant of `ld` is useful when loading symbols that may be undefined at
      runtime, such as composite symbols, and whether they are defined or not cannot
      be determined statically. For example `d['a']` is undefined when `d` is an
      empty dict.
  
      Args:
        load_v: Lambda that executes the actual read.
        name: Human-readable name of the symbol being read.
      Returns:
        Either the value of the symbol, or Undefined, if the symbol is not fully
        defined.
      """
      try:
          # TODO(mdan): Use locals()/globals() here.
          return load_v()
      except (KeyError, AttributeError, NameError):
          return Undefined(name)
  
file_path: tensorflow/tensorflow/python/autograph/operators/variables.py
label_desc: Use image node_id 2 for calling a global function with example usage: ldu(load_v, name) and returns: load_v, Undefined