What is the definition of the error code 2154 for Chromecast?

After successfully connecting then disconnecting an Android phone from Chromecast, my class' CastSessionManagerListener.onSessionEnded(session: CastSession, error: Int) returns error as 2154, and CastStatusCodes.getStatusCodeString(error) returns unknown status code: 2154. The error code is not documented and it's coming from the Chromecast library. I'd like to know what the cause is or if I can safely ignore it.