code: def format_link_json(self):
          
          link_json = {}
          link_json['trace_id'] = self.trace_id
          link_json['span_id'] = self.span_id
          link_json['type'] = self.type
  
          if self.attributes is not None:
              link_json['attributes'] = self.attributes
  
          return link_json
docs: Convert a Link object to json format.