https://www.graalvm.org/ 
class com.oracle.truffle.api.nodes.NodeClassImpl$5 implements com.oracle.truffle.api.nodes.NodeClassImpl$NodeFieldFilter
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.nodes.NodeClassImpl$5
  super_class: java.lang.Object
{
  final com.oracle.truffle.api.nodes.NodeClassImpl this$0;
    descriptor: Lcom/oracle/truffle/api/nodes/NodeClassImpl;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  void <init>(com.oracle.truffle.api.nodes.NodeClassImpl);
    descriptor: (Lcom/oracle/truffle/api/nodes/NodeClassImpl;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.nodes.NodeClassImpl$5 this
         0: .line 263
            aload 0 /* this */
            aload 1
            putfield com.oracle.truffle.api.nodes.NodeClassImpl$5.this$0:Lcom/oracle/truffle/api/nodes/NodeClassImpl;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // com.oracle.truffle.api.nodes.NodeClassImpl$5 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/nodes/NodeClassImpl$5;
    MethodParameters:
        Name  Flags
      this$0  final

  public boolean test(com.oracle.truffle.api.nodes.NodeFieldAccessor);
    descriptor: (Lcom/oracle/truffle/api/nodes/NodeFieldAccessor;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.nodes.NodeClassImpl$5 this
        start local 1 // com.oracle.truffle.api.nodes.NodeFieldAccessor field
         0: .line 265
            aload 0 /* this */
            getfield com.oracle.truffle.api.nodes.NodeClassImpl$5.this$0:Lcom/oracle/truffle/api/nodes/NodeClassImpl;
            aload 1 /* field */
            invokevirtual com.oracle.truffle.api.nodes.NodeClassImpl.isCloneableField:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // com.oracle.truffle.api.nodes.NodeFieldAccessor field
        end local 0 // com.oracle.truffle.api.nodes.NodeClassImpl$5 this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    1     0   this  Lcom/oracle/truffle/api/nodes/NodeClassImpl$5;
            0    1     1  field  Lcom/oracle/truffle/api/nodes/NodeFieldAccessor;
    MethodParameters:
       Name  Flags
      field  
}
SourceFile: "NodeClassImpl.java"
EnclosingMethod: com.oracle.truffle.api.nodes.NodeClassImpl.getCloneableFields:()[Lcom/oracle/truffle/api/nodes/NodeFieldAccessor;
NestHost: com.oracle.truffle.api.nodes.NodeClassImpl
InnerClasses:
  com.oracle.truffle.api.nodes.NodeClassImpl$5
  private abstract NodeFieldFilter = com.oracle.truffle.api.nodes.NodeClassImpl$NodeFieldFilter of com.oracle.truffle.api.nodes.NodeClassImpl