@can.onPatches( handler(patches), queueName )

The @can.onPatches symbol points to a function that registers handler to be called back with an array of changes that have happened on the client.

The following mutations on a list-like object will produce the patch objects in the comments:

const list = [];

list.count = 3000; //-> {type: "add", key: "count", 3000}

list.push( "a" ); //-> {type: "splice", index: 0, insert: ["a"]}