docs: def set( string, target_level, indent_string="    ", indent_empty_lines=False ):
      """ Sets indentation of a single/multi-line string. """
  
      lines = string.splitlines()
      set_lines( lines, target_level, indent_string=indent_string, indent_empty_lines=indent_empty_lines )
      result = "\n".join(lines)
      return result