code: def re_line_and_indentation(base_indentation,
                              modifiers=(True, True)):
      
      cache = re_line_and_indentation.cache[modifiers]
      compiled = cache.get(base_indentation, None)
      if compiled is None:
          [prefix, suffix] = re_line_and_indentation.tuple[modifiers]
          compiled = cache[modifiers] = \
              _re.compile(prefix + base_indentation + suffix)
      return compiled
docs: Returns a re matching newline + base_indentation.
  
      modifiers is a tuple, (include_first, include_final).
  
      If include_first, matches indentation at the beginning of the string.
      If include_final, matches indentation at the end of the string.
  
      Cached.