code: function _promiseRejectionHandler(event) {
  	    this._logDebug('debug', 'Raven caught unhandled promise rejection:', event);
  
  	    this.captureException(event.reason, {
  	      mechanism: {
  	        type: 'onunhandledrejection',
  	        handled: false
  	      }
  	    });
  	  }
docs: Callback used for `unhandledrejection` event
  
  @param {PromiseRejectionEvent} event An object containing
  promise: the Promise that was rejected
  reason: the value with which the Promise was rejected
  @return void