can-map.js
function(attr){
			if(!unobservable[attr] && !this._computedAttrs[attr]) {
				ObservationRecorder.add(this, attr);
			}
			return this.___get( attr );
		}
function(attr){
			if(!unobservable[attr] && !this._computedAttrs[attr]) {
				ObservationRecorder.add(this, attr);
			}
			return this.___get( attr );
		}
### __get Signals `can.compute` that an observable property is being read.