code: def filename():
      """
      Return the name of the file currently being read.
      Before the first line has been read, returns None.
      """
      if not _state:
          raise RuntimeError("no active input()")
      return _state.filename()
  
imports: import io
  import sys, os
  from types import GenericAlias
label_desc: Use image node_id 4 for calling a global function with example usage: filename() and returns: _state