docs: def text_normalize(text):
      """
      Whitespace normalization:
  
        - Strip empty lines
        - Strip leading whitespace  in a line
        - Strip trailing whitespace in a line
        - Normalize line endings
      """
      # if not isinstance(text, str):
      if isinstance(text, bytes):
          # -- MAYBE: command.ouput => bytes, encoded stream output.
          text = codecs.decode(text)
      lines = [ line.strip()  for line in text.splitlines()  if line.strip() ]
      return "\n".join(lines)