code: function saveDepths(depths, callback) {
  
    async.parallel([
        async.apply(store.getStore().setDepth.bind(store.getStore()), depths.parentUrl, depths.parentDepth ),
        async.apply(store.getStore().setDepth.bind(store.getStore()), depths.linkUri, depths.linkDepth )
    ],
    function(error){
        callback(error, depths);
    });
  }
docs: Save the crawl depths for a parent & link uri
  
  
  @param a structure containing both url
  {parentUrl : parentUrl, linkUri : linkUri}
  @param callback(error, depth)