code: protected static void assertion(boolean b, String msg)
    {
    	if(!b)
    	{
    		throw new RuntimeException(XSLMessages.createMessage(XSLTErrorResources.ER_ASSERT_REDUNDENT_EXPR_ELIMINATOR, new Object[]{msg}));
    		// "Programmer's assertion in RundundentExprEliminator: "+msg);
    	}
    }
docs: Simple assertion.