code: function initRelations(component, isPage) {
      let relations = component.relations;
      if (!relations || isPage) {
          // relations only support component, page is not supported
          return;
      }
  
      // normalize relation `target` information
      Object.keys(relations).forEach(k => {
          let item = relations[k];
          let {target} = item;
          if (typeof target === 'function') {
              target = target();
              item.target = target.behavior;
          }
      });
  }
docs: Initialize the component relations
  
  @inner
  @param {Object} component the component info
  @param {boolean} isPage whether is the page component