code: def node_edge(self, node, edge, fields=None, params=None):
  
          
          if fields:
              fields = ",".join(fields)
  
          parameters = {"fields": fields,
                        "access_token": self.key}
          parameters = self.merge_params(parameters, params)
  
          return self.api_call('%s/%s' % (node, edge), parameters)
docs: :param node:
          :param edge:
          :param fields:
          :param params:
          :return: