question: public void throwIfNecessary ( ) { if ( ! failureList . isEmpty ( ) ) { RuntimeException ex = null ; for ( AISValidationFailure f : failureList ) { LOG . debug ( String . format ( "Validation failure %s : %s" , f . errorCode ( ) , f . message ( ) ) ) ; ex = MultipleCauseException . combine ( ex , f . getException ( ) ) ; } throw ex ; } }
target:  Throws an InvalidOperationException if failures() returns a non-null collection.