question: @ SuppressWarnings ( "unchecked" ) private static < T > void assertThrows ( final Consumer < Void > consumer , final Class < T > exceptionClass , final Consumer < T > assertExceptionProperties , final String message ) { final String normalizedMessage = null == message ? "" : String . format ( "[%s]: " , message ) ; try { consumer . accept ( null ) ; } catch ( final Exception ex ) { if ( exceptionClass . isAssignableFrom ( ex . getClass ( ) ) ) { assertExceptionProperties . accept ( ( T ) ex ) ; return ; } Assert . fail ( String . format ( "%sunexpected exception of type %s was thrown: '%s'" , normalizedMessage , ex . getClass ( ) , ex . getMessage ( ) ) ) ; } Assert . fail ( String . format ( "%sexpected exception of type %s was not thrown" , normalizedMessage , exceptionClass ) ) ; }
target:  Asserts that the execution of consumer throws an exception of the specific class.