code: def get_qp_ctext(value):
      
      ptext, value, _ = _get_ptext_to_endchars(value, '()')
      ptext = WhiteSpaceTerminal(ptext, 'ptext')
      _validate_xtext(ptext)
      return ptext, value
docs: ctext = <printable ascii except \ ( )>
  
      This is not the RFC ctext, since we are handling nested comments in comment
      and unquoting quoted-pairs here.  We allow anything except the '()'
      characters, but if we find any ASCII other than the RFC defined printable
      ASCII an NonPrintableDefect is added to the token's defects list.  Since
      quoted pairs are converted to their unquoted values, what is returned is
      a 'ptext' token.  In this case it is a WhiteSpaceTerminal, so it's value
      is ' '.