@@ -0,0 +1,650 @@
+const Linked = require('./Linked')%0Aconst Node = require('./Node')%0A%0Aclass Queue extends Linked %7B%0A  constructor() %7B%0A    super()%0A    this.last = null%0A  %7D%0A  enqueue(item) %7B%0A    const oldLast = this.last%0A    this.last = new Node()%0A    this.last.item = item%0A    this.last.next = null%0A    if (this.isEmpty() === true) %7B%0A      this.first = this.last%0A    %7D else %7B%0A      oldLast.next = this.last%0A    %7D%0A    this.N = this.N + 1%0A    return this%0A  %7D%0A  dequeue() %7B%0A    const item = this.first.item%0A    this.first = this.first.next%0A    if (this.isEmpty() === true) %7B%0A      this.last = null%0A    %7D%0A    this.N = this.N - 1%0A    return item%0A  %7D%0A%7D%0A%0Amodule.exports = Queue%0A

refactor push()