text: 'use strict';
  
  // ==============================
  // ABSTRACT COLLEAGUE 
  // ==============================
  
  var Neighbor = function(mediator) {
      if (this.constructor === Neighbor) {
          throw new Error("You cannot instantiate an abstract class!");
      }
      this._mediator = mediator;
  }
  
  Neighbor.prototype.send = function (message) {
      throw new Error("You cannot instantiate an abstract class!");
  };
  
  Neighbor.prototype.receive = function (message, sender) {
      throw new Error("You cannot instantiate an abstract class!");
  };
  
  module.exports = Neighbor;
  