docs: function Event(type, properties, timestamp) {
  		this.type = type;
  		this.properties = properties;
  
  		if (timestamp === undefined) {
  			this.timestamp = moment.utc();
  		}
  		else {
  			this.timestamp = moment.utc(timestamp);
  		}
  
  		this.timestamp = this.timestamp.format('YYYY-MM-DDTHH:mm:ss.SSS') + 'Z';
  	}