question: private static void check ( MethodDesc prev , MethodDesc desc ) { if ( prev . types == null || Arrays . equals ( prev . types , desc . types ) ) { StringBuffer buf = new StringBuffer ( ) ; prev . toString ( buf , false ) ; buf . append ( " cannot precede " ) ; desc . toString ( buf , false ) ; throw new IllegalArgumentException ( buf . toString ( ) ) ; } }
target:  Throws IllegalArgumentException if the parameter types of prev cover those of desc.