code: function(x, y, obj) {
              if(typeof obj === 'string'){
                  obj = this.makeNewObjectFromType(obj);
              }
              obj.game = this.game;
              obj.x = x;
              obj.y = y;
              this.objects.push(obj);
              var arr = this.map.get(x, y);
              arr.push(obj);
              if(obj.onAdd){
                  obj.onAdd();
              }
              return obj;
          }
docs: Adds an object to the manager at given map tile coord. Multiple objects can be added to the same coord.
  @method add
  @param {Number} x - Map tile coord x.
  @param {Number} y - Map tile coord y.
  @param {Object|String} obj - The Object being set at given coords. If `obj` is a string a new Object will be created using `this.makeNewObjectFromType(obj)`.
  @return {Object} The added object.