code: def __trailing_newline(eof):
      """
        Helper function returning an empty string or a newling character to
      append to the current output line depending on whether we want that line to
      be the last line in the file (eof == True) or not (eof == False).
  
      """
      if eof:
          return ""
      return "\n"
  
imports: import BoostBuild
label_desc: Use image node_id 5 for calling a global function with example usage: __trailing_newline(eof) and returns: str, str