code: function (emitter, emitterName) {
              // ennumerable MUST be set `true` to enable merging
              Object.defineProperty(emitter, '_emitterName', {
                  configurable: false,
                  enumerable: true,
                  writable: false,
                  value: emitterName
              });
          }
docs: Defines an emitterName into the instance (emitter).
  This will add a protected property `_emitterName` to the instance.
  
  @static
  @method defineEmitter
  @param emitter {Object} instance that should hold the emitterName
  @param emitterName {String} identifier that will be added when events are sent (`emitterName:eventName`)
  @since 0.0.1