code: def to_dict(self):
          
          d = {}
          if self.query_params_match is not None:
              d['@query_params_match'] = self.query_params_match
          if self.sources:
              d['sources'] = [source.to_dict() for source in self.sources]
          d.update(self.fields_to_dict())
          return d
docs: Return a dict representation of the person.