Obtain either all notifications from CommonSense, or the details of a specific notification.
            If successful, the result can be obtained from getResponse(), and should be a json string.
            
            @param notification_id (int) (optional) - Notification id of the notification to obtain details from.
            
            @return (bool) - Boolean indicating whether NotificationsGet was successful.

def NotificationsGet(self, notification_id = -1):
        """
            Obtain either all notifications from CommonSense, or the details of a specific notification.
            If successful, the result can be obtained from getResponse(), and should be a json string.
            
            @param notification_id (int) (optional) - Notification id of the notification to obtain details from.
            
            @return (bool) - Boolean indicating whether NotificationsGet was successful.
        """
        if notification_id == -1:
            url = '/notifications.json'
        else:
            url = '/notifications/{0}.json'.format(notification_id)

        if self.__SenseApiCall__(url, 'GET'):
            return True
        else:
            self.__error__ = "api call unsuccessful"
            return False