code: def parse_headerline(self, line):
          
          if self._end_header is True:
              # Header already processed
              return 0
  
          splitted = [token.strip() for token in line.split(',')]
          if splitted[-1] == 'end':
              self._keywords = splitted[1:-1]  # exclude the word end
              self._end_header = True
          return 0
docs: Parses header lines
  
              Keywords example:
              Keyword1, Keyword2, Keyword3, ..., end