code: def Parse(self, raw_data):
      
      self.results = set()
      if not self.filters:
        self.results.update(raw_data)
      else:
        for f in self.filters:
          self.results.update(f.Parse(raw_data))
      return list(self.results)
docs: Take the data and yield results that passed through the filters.
  
      The output of each filter is added to a result set. So long as the filter
      selects, but does not modify, raw data, the result count will remain
      accurate.
  
      Args:
        raw_data: An iterable series of rdf values.
  
      Returns:
        A list of rdf values that matched at least one filter.