question: public static boolean isNonPublicProxyClass ( Class < ? > cls ) { String name = cls . getName ( ) ; int i = name . lastIndexOf ( '.' ) ; String pkg = ( i != - 1 ) ? name . substring ( 0 , i ) : "" ; return Proxy . isProxyClass ( cls ) && ! pkg . equals ( PROXY_PACKAGE ) ; }
target:  Test if the given class is a proxy class that implements non-public interface.  Such proxy class may be in a non-restricted package that bypasses checkPackageAccess.