https://www.graalvm.org/ 
final class com.oracle.truffle.api.frame.FrameAccessor$FramesImpl extends com.oracle.truffle.api.impl.Accessor$FrameSupport
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.oracle.truffle.api.frame.FrameAccessor$FramesImpl
  super_class: com.oracle.truffle.api.impl.Accessor$FrameSupport
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.frame.FrameAccessor$FramesImpl this
         0: .line 49
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.impl.Accessor$FrameSupport.<init>:()V
            return
        end local 0 // com.oracle.truffle.api.frame.FrameAccessor$FramesImpl this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/frame/FrameAccessor$FramesImpl;

  public void markMaterializeCalled(com.oracle.truffle.api.frame.FrameDescriptor);
    descriptor: (Lcom/oracle/truffle/api/frame/FrameDescriptor;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.frame.FrameAccessor$FramesImpl this
        start local 1 // com.oracle.truffle.api.frame.FrameDescriptor descriptor
         0: .line 52
            aload 1 /* descriptor */
            iconst_1
            putfield com.oracle.truffle.api.frame.FrameDescriptor.materializeCalled:Z
         1: .line 53
            return
        end local 1 // com.oracle.truffle.api.frame.FrameDescriptor descriptor
        end local 0 // com.oracle.truffle.api.frame.FrameAccessor$FramesImpl this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    2     0        this  Lcom/oracle/truffle/api/frame/FrameAccessor$FramesImpl;
            0    2     1  descriptor  Lcom/oracle/truffle/api/frame/FrameDescriptor;
    MethodParameters:
            Name  Flags
      descriptor  

  public boolean getMaterializeCalled(com.oracle.truffle.api.frame.FrameDescriptor);
    descriptor: (Lcom/oracle/truffle/api/frame/FrameDescriptor;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.frame.FrameAccessor$FramesImpl this
        start local 1 // com.oracle.truffle.api.frame.FrameDescriptor descriptor
         0: .line 57
            aload 1 /* descriptor */
            getfield com.oracle.truffle.api.frame.FrameDescriptor.materializeCalled:Z
            ireturn
        end local 1 // com.oracle.truffle.api.frame.FrameDescriptor descriptor
        end local 0 // com.oracle.truffle.api.frame.FrameAccessor$FramesImpl this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    1     0        this  Lcom/oracle/truffle/api/frame/FrameAccessor$FramesImpl;
            0    1     1  descriptor  Lcom/oracle/truffle/api/frame/FrameDescriptor;
    MethodParameters:
            Name  Flags
      descriptor  
}
SourceFile: "FrameAccessor.java"
NestHost: com.oracle.truffle.api.frame.FrameAccessor
InnerClasses:
  final FramesImpl = com.oracle.truffle.api.frame.FrameAccessor$FramesImpl of com.oracle.truffle.api.frame.FrameAccessor
  public abstract FrameSupport = com.oracle.truffle.api.impl.Accessor$FrameSupport of com.oracle.truffle.api.impl.Accessor