/**
 * We get the node interface and field from the Relay library.
 *
 * The first method defines the way we resolve an ID to its object.
 * The second defines the way we resolve an object to its GraphQL type.
 */
var {nodeInterface, nodeField} = nodeDefinitions(
  (globalId) => {
    var {type, id} = fromGlobalId(globalId);
    if (type === 'PowerDatum') {
      return getUser(id);
    } else if (type === 'Widget') {
      return getWidget(id);
    } else {
      return null;
    }
  },
  (obj) => {
    if (obj instanceof User) {
      return userType;
    } else if (obj instanceof Widget)  {
      return widgetType;
    } else {
      return null;
    }
  }
);