code: def preprocess(msg_body, delimiter, content_type='text/plain'):
      
      msg_body = _replace_link_brackets(msg_body)
  
      msg_body = _wrap_splitter_with_newline(msg_body, delimiter, content_type)
  
      return msg_body
docs: Prepares msg_body for being stripped.
  
      Replaces link brackets so that they couldn't be taken for quotation marker.
      Splits line in two if splitter pattern preceded by some text on the same
      line (done only for 'On <date> <person> wrote:' pattern).
  
      Converts msg_body into a unicode.