question: private int processError ( L10NMessageImpl e , String headerMessageCode , String debugMessage , Object ... messageParameters ) throws AuthLoginException { if ( null == e ) { return processError ( headerMessageCode , debugMessage , messageParameters ) ; } String headerMessage ; if ( null == headerMessageCode ) { headerMessage = e . getL10NMessage ( getLoginLocale ( ) ) ; } else { headerMessage = bundle . getString ( headerMessageCode ) ; } if ( debugMessage != null ) { DEBUG . error ( debugMessage , messageParameters , e ) ; } substituteHeader ( STATE_ERROR , headerMessage ) ; return STATE_ERROR ; }
target:  Writes out an error debug (if a throwable and debug message are provided) and returns a user-facing error page.