asm traceClassVisitor用法

            TraceClassVisitor cv = new TraceClassVisitor(cw, new PrintWriter(System.err));
            cv.visit(Opcodes.V1_5, Opcodes.ACC_PUBLIC + Opcodes.ACC_ABSTRACT + Opcodes.ACC_INTERFACE,
                     "qssq/asm/examples/Comparable", null, "java/lang/Object",
                     new String[] { "test/asm/examples/Mesurable" });
            cv.visitField(Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_STATIC, "LESS", "I", null, new Integer(-1)).visitEnd();
            cv.visitField(Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_STATIC, "EQUAL", "I", null, new Integer(0)).visitEnd();
            cv.visitField(Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_STATIC, "GREATER", "I", null, new Integer(1)).visitEnd();
            cv.visitMethod(Opcodes.ACC_PUBLIC + Opcodes.ACC_ABSTRACT, "compareTo", "(Ljava/lang/Object;)I", null, null).visitEnd();