https://github.com/cglib/cglib/cglib: cglib is a powerful, high performance and quality Code Generation Library, It is used to extend JAVA classes and implements interfaces at runtime. 
class net.sf.cglib.proxy.Enhancer$1 implements net.sf.cglib.proxy.CallbackFilter
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: net.sf.cglib.proxy.Enhancer$1
  super_class: java.lang.Object
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // net.sf.cglib.proxy.Enhancer$1 this
         0: .line 65
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // net.sf.cglib.proxy.Enhancer$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lnet/sf/cglib/proxy/Enhancer$1;

  public int accept(java.lang.reflect.Method);
    descriptor: (Ljava/lang/reflect/Method;)I
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=2, args_size=2
        start local 0 // net.sf.cglib.proxy.Enhancer$1 this
        start local 1 // java.lang.reflect.Method method
         0: .line 67
            iconst_0
            ireturn
        end local 1 // java.lang.reflect.Method method
        end local 0 // net.sf.cglib.proxy.Enhancer$1 this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    1     0    this  Lnet/sf/cglib/proxy/Enhancer$1;
            0    1     1  method  Ljava/lang/reflect/Method;
    MethodParameters:
        Name  Flags
      method  
}
SourceFile: "Enhancer.java"
EnclosingMethod: net.sf.cglib.proxy.Enhancer
NestHost: net.sf.cglib.proxy.Enhancer
InnerClasses:
  net.sf.cglib.proxy.Enhancer$1