Method serialize

packages/router/test/create_url_tree.spec.ts:786–798

(tree: UrlTree)

      return tree;
    }
    override serialize(tree: UrlTree): string {
      const qp: {[key: string]: any} = {};
      Object.keys(tree.queryParams).forEach((key) => {
        const value = tree.queryParams[key];
        if (typeof value === 'object' && value !== null) {
          qp[key] = JSON.stringify(value);
        } else {
          qp[key] = value;
        }
      });
      tree.queryParams = qp;
      return super.serialize(tree);
    }
  }

  beforeEach(() => {