code: func (s *Scanner) Separator() []byte {
  	if s.separator == nil {
  		if found := s.Scan(); !found {
  			if err := s.Err(); err != nil {
  				panic(err)
  			}
  			return _DEF_SEPARATOR
  		}
  	}
  	return s.separator
  }
docs: // Separator returns the character/s used to separate the key from the value.
  //
  // The separator is got in the first call to "Scan()"; if it has not been
  // called, this makes it explicitly but panics when there is any error.