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. 
public class net.sf.cglib.proxy.InterfaceMaker extends net.sf.cglib.core.AbstractClassGenerator
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: net.sf.cglib.proxy.InterfaceMaker
  super_class: net.sf.cglib.core.AbstractClassGenerator
{
  private static final net.sf.cglib.core.AbstractClassGenerator$Source SOURCE;
    descriptor: Lnet/sf/cglib/core/AbstractClassGenerator$Source;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private java.util.Map signatures;
    descriptor: Ljava/util/Map;
    flags: (0x0002) ACC_PRIVATE

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=3, locals=0, args_size=0
         0: .line 34
            new net.sf.cglib.core.AbstractClassGenerator$Source
            dup
            ldc Lnet/sf/cglib/proxy/InterfaceMaker;
            invokevirtual java.lang.Class.getName:()Ljava/lang/String;
            invokespecial net.sf.cglib.core.AbstractClassGenerator$Source.<init>:(Ljava/lang/String;)V
            putstatic net.sf.cglib.proxy.InterfaceMaker.SOURCE:Lnet/sf/cglib/core/AbstractClassGenerator$Source;
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
         0: .line 43
            aload 0 /* this */
            getstatic net.sf.cglib.proxy.InterfaceMaker.SOURCE:Lnet/sf/cglib/core/AbstractClassGenerator$Source;
            invokespecial net.sf.cglib.core.AbstractClassGenerator.<init>:(Lnet/sf/cglib/core/AbstractClassGenerator$Source;)V
         1: .line 35
            aload 0 /* this */
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
            putfield net.sf.cglib.proxy.InterfaceMaker.signatures:Ljava/util/Map;
         2: .line 44
            return
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lnet/sf/cglib/proxy/InterfaceMaker;

  public void add(net.sf.cglib.core.Signature, org.objectweb.asm.Type[]);
    descriptor: (Lnet/sf/cglib/core/Signature;[Lorg/objectweb/asm/Type;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
        start local 1 // net.sf.cglib.core.Signature sig
        start local 2 // org.objectweb.asm.Type[] exceptions
         0: .line 52
            aload 0 /* this */
            getfield net.sf.cglib.proxy.InterfaceMaker.signatures:Ljava/util/Map;
            aload 1 /* sig */
            aload 2 /* exceptions */
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 53
            return
        end local 2 // org.objectweb.asm.Type[] exceptions
        end local 1 // net.sf.cglib.core.Signature sig
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    2     0        this  Lnet/sf/cglib/proxy/InterfaceMaker;
            0    2     1         sig  Lnet/sf/cglib/core/Signature;
            0    2     2  exceptions  [Lorg/objectweb/asm/Type;
    MethodParameters:
            Name  Flags
      sig         
      exceptions  

  public void add(java.lang.reflect.Method);
    descriptor: (Ljava/lang/reflect/Method;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
        start local 1 // java.lang.reflect.Method method
         0: .line 61
            aload 0 /* this */
            aload 1 /* method */
            invokestatic net.sf.cglib.core.ReflectUtils.getSignature:(Ljava/lang/reflect/Member;)Lnet/sf/cglib/core/Signature;
         1: .line 62
            aload 1 /* method */
            invokestatic net.sf.cglib.core.ReflectUtils.getExceptionTypes:(Ljava/lang/reflect/Member;)[Lorg/objectweb/asm/Type;
         2: .line 61
            invokevirtual net.sf.cglib.proxy.InterfaceMaker.add:(Lnet/sf/cglib/core/Signature;[Lorg/objectweb/asm/Type;)V
         3: .line 63
            return
        end local 1 // java.lang.reflect.Method method
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    4     0    this  Lnet/sf/cglib/proxy/InterfaceMaker;
            0    4     1  method  Ljava/lang/reflect/Method;
    MethodParameters:
        Name  Flags
      method  

  public void add(java.lang.Class);
    descriptor: (Ljava/lang/Class;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=5, args_size=2
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
        start local 1 // java.lang.Class clazz
         0: .line 72
            aload 1 /* clazz */
            invokevirtual java.lang.Class.getMethods:()[Ljava/lang/reflect/Method;
            astore 2 /* methods */
        start local 2 // java.lang.reflect.Method[] methods
         1: .line 73
            iconst_0
            istore 3 /* i */
        start local 3 // int i
         2: goto 7
         3: .line 74
      StackMap locals: java.lang.reflect.Method[] int
      StackMap stack:
            aload 2 /* methods */
            iload 3 /* i */
            aaload
            astore 4 /* m */
        start local 4 // java.lang.reflect.Method m
         4: .line 75
            aload 4 /* m */
            invokevirtual java.lang.reflect.Method.getDeclaringClass:()Ljava/lang/Class;
            invokevirtual java.lang.Class.getName:()Ljava/lang/String;
            ldc "java.lang.Object"
            invokevirtual java.lang.String.equals:(Ljava/lang/Object;)Z
            ifne 6
         5: .line 76
            aload 0 /* this */
            aload 4 /* m */
            invokevirtual net.sf.cglib.proxy.InterfaceMaker.add:(Ljava/lang/reflect/Method;)V
        end local 4 // java.lang.reflect.Method m
         6: .line 73
      StackMap locals:
      StackMap stack:
            iinc 3 /* i */ 1
      StackMap locals:
      StackMap stack:
         7: iload 3 /* i */
            aload 2 /* methods */
            arraylength
            if_icmplt 3
        end local 3 // int i
         8: .line 79
            return
        end local 2 // java.lang.reflect.Method[] methods
        end local 1 // java.lang.Class clazz
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    9     0     this  Lnet/sf/cglib/proxy/InterfaceMaker;
            0    9     1    clazz  Ljava/lang/Class;
            1    9     2  methods  [Ljava/lang/reflect/Method;
            2    8     3        i  I
            4    6     4        m  Ljava/lang/reflect/Method;
    MethodParameters:
       Name  Flags
      clazz  

  public java.lang.Class create();
    descriptor: ()Ljava/lang/Class;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
         0: .line 85
            aload 0 /* this */
            iconst_0
            invokevirtual net.sf.cglib.proxy.InterfaceMaker.setUseCache:(Z)V
         1: .line 86
            aload 0 /* this */
            aload 0 /* this */
            invokespecial net.sf.cglib.core.AbstractClassGenerator.create:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.lang.Class
            areturn
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lnet/sf/cglib/proxy/InterfaceMaker;

  protected java.lang.ClassLoader getDefaultClassLoader();
    descriptor: ()Ljava/lang/ClassLoader;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
         0: .line 90
            aconst_null
            areturn
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lnet/sf/cglib/proxy/InterfaceMaker;

  protected java.lang.Object firstInstance(java.lang.Class);
    descriptor: (Ljava/lang/Class;)Ljava/lang/Object;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=1, locals=2, args_size=2
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
        start local 1 // java.lang.Class type
         0: .line 94
            aload 1 /* type */
            areturn
        end local 1 // java.lang.Class type
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lnet/sf/cglib/proxy/InterfaceMaker;
            0    1     1  type  Ljava/lang/Class;
    MethodParameters:
      Name  Flags
      type  

  protected java.lang.Object nextInstance(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
        start local 1 // java.lang.Object instance
         0: .line 98
            new java.lang.IllegalStateException
            dup
            ldc "InterfaceMaker does not cache"
            invokespecial java.lang.IllegalStateException.<init>:(Ljava/lang/String;)V
            athrow
        end local 1 // java.lang.Object instance
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    1     0      this  Lnet/sf/cglib/proxy/InterfaceMaker;
            0    1     1  instance  Ljava/lang/Object;
    MethodParameters:
          Name  Flags
      instance  

  public void generateClass(org.objectweb.asm.ClassVisitor);
    descriptor: (Lorg/objectweb/asm/ClassVisitor;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=7, locals=6, args_size=2
        start local 0 // net.sf.cglib.proxy.InterfaceMaker this
        start local 1 // org.objectweb.asm.ClassVisitor v
         0: .line 102
            new net.sf.cglib.core.ClassEmitter
            dup
            aload 1 /* v */
            invokespecial net.sf.cglib.core.ClassEmitter.<init>:(Lorg/objectweb/asm/ClassVisitor;)V
            astore 2 /* ce */
        start local 2 // net.sf.cglib.core.ClassEmitter ce
         1: .line 103
            aload 2 /* ce */
            bipush 52
         2: .line 104
            sipush 1537
         3: .line 105
            aload 0 /* this */
            invokevirtual net.sf.cglib.proxy.InterfaceMaker.getClassName:()Ljava/lang/String;
         4: .line 106
            aconst_null
         5: .line 107
            aconst_null
         6: .line 108
            ldc "<generated>"
         7: .line 103
            invokevirtual net.sf.cglib.core.ClassEmitter.begin_class:(IILjava/lang/String;Lorg/objectweb/asm/Type;[Lorg/objectweb/asm/Type;Ljava/lang/String;)V
         8: .line 109
            aload 0 /* this */
            getfield net.sf.cglib.proxy.InterfaceMaker.signatures:Ljava/util/Map;
            invokeinterface java.util.Map.keySet:()Ljava/util/Set;
            invokeinterface java.util.Set.iterator:()Ljava/util/Iterator;
            astore 3 /* it */
        start local 3 // java.util.Iterator it
         9: goto 17
        10: .line 110
      StackMap locals: net.sf.cglib.core.ClassEmitter java.util.Iterator
      StackMap stack:
            aload 3 /* it */
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast net.sf.cglib.core.Signature
            astore 4 /* sig */
        start local 4 // net.sf.cglib.core.Signature sig
        11: .line 111
            aload 0 /* this */
            getfield net.sf.cglib.proxy.InterfaceMaker.signatures:Ljava/util/Map;
            aload 4 /* sig */
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.objectweb.asm.Type[]
            astore 5 /* exceptions */
        start local 5 // org.objectweb.asm.Type[] exceptions
        12: .line 112
            aload 2 /* ce */
            sipush 1025
        13: .line 113
            aload 4 /* sig */
        14: .line 114
            aload 5 /* exceptions */
        15: .line 112
            invokevirtual net.sf.cglib.core.ClassEmitter.begin_method:(ILnet/sf/cglib/core/Signature;[Lorg/objectweb/asm/Type;)Lnet/sf/cglib/core/CodeEmitter;
        16: .line 114
            invokevirtual net.sf.cglib.core.CodeEmitter.end_method:()V
        end local 5 // org.objectweb.asm.Type[] exceptions
        end local 4 // net.sf.cglib.core.Signature sig
        17: .line 109
      StackMap locals:
      StackMap stack:
            aload 3 /* it */
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 10
        end local 3 // java.util.Iterator it
        18: .line 116
            aload 2 /* ce */
            invokevirtual net.sf.cglib.core.ClassEmitter.end_class:()V
        19: .line 117
            return
        end local 2 // net.sf.cglib.core.ClassEmitter ce
        end local 1 // org.objectweb.asm.ClassVisitor v
        end local 0 // net.sf.cglib.proxy.InterfaceMaker this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0   20     0        this  Lnet/sf/cglib/proxy/InterfaceMaker;
            0   20     1           v  Lorg/objectweb/asm/ClassVisitor;
            1   20     2          ce  Lnet/sf/cglib/core/ClassEmitter;
            9   18     3          it  Ljava/util/Iterator;
           11   17     4         sig  Lnet/sf/cglib/core/Signature;
           12   17     5  exceptions  [Lorg/objectweb/asm/Type;
    Exceptions:
      throws java.lang.Exception
    MethodParameters:
      Name  Flags
      v     
}
SourceFile: "InterfaceMaker.java"
InnerClasses:
  protected Source = net.sf.cglib.core.AbstractClassGenerator$Source of net.sf.cglib.core.AbstractClassGenerator