https://www.graalvm.org/ 
class com.oracle.truffle.api.test.FrameTest$1FrameRootNode extends com.oracle.truffle.api.nodes.RootNode
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.test.FrameTest$1FrameRootNode
  super_class: com.oracle.truffle.api.nodes.RootNode
{
  final com.oracle.truffle.api.test.FrameTest this$0;
    descriptor: Lcom/oracle/truffle/api/test/FrameTest;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private final com.oracle.truffle.api.TruffleRuntime val$runtime;
    descriptor: Lcom/oracle/truffle/api/TruffleRuntime;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  void <init>(com.oracle.truffle.api.test.FrameTest, com.oracle.truffle.api.TruffleRuntime);
    descriptor: (Lcom/oracle/truffle/api/test/FrameTest;Lcom/oracle/truffle/api/TruffleRuntime;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.oracle.truffle.api.test.FrameTest$1FrameRootNode this
         0: .line 181
            aload 0 /* this */
            aload 1
            putfield com.oracle.truffle.api.test.FrameTest$1FrameRootNode.this$0:Lcom/oracle/truffle/api/test/FrameTest;
            aload 0 /* this */
            aload 2
            putfield com.oracle.truffle.api.test.FrameTest$1FrameRootNode.val$runtime:Lcom/oracle/truffle/api/TruffleRuntime;
         1: .line 182
            aload 0 /* this */
            aconst_null
            invokespecial com.oracle.truffle.api.nodes.RootNode.<init>:(Lcom/oracle/truffle/api/TruffleLanguage;)V
         2: .line 183
            return
        end local 0 // com.oracle.truffle.api.test.FrameTest$1FrameRootNode this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/api/test/FrameTest$1FrameRootNode;
    MethodParameters:
             Name  Flags
      this$0       final
      val$runtime  final

  public java.lang.Object execute(com.oracle.truffle.api.frame.VirtualFrame);
    descriptor: (Lcom/oracle/truffle/api/frame/VirtualFrame;)Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=5, args_size=2
        start local 0 // com.oracle.truffle.api.test.FrameTest$1FrameRootNode this
        start local 1 // com.oracle.truffle.api.frame.VirtualFrame frame
         0: .line 187
            aload 0 /* this */
            getfield com.oracle.truffle.api.test.FrameTest$1FrameRootNode.val$runtime:Lcom/oracle/truffle/api/TruffleRuntime;
            invokeinterface com.oracle.truffle.api.TruffleRuntime.getCurrentFrame:()Lcom/oracle/truffle/api/frame/FrameInstance;
            astore 2 /* frameInstance */
        start local 2 // com.oracle.truffle.api.frame.FrameInstance frameInstance
         1: .line 188
            aload 2 /* frameInstance */
            getstatic com.oracle.truffle.api.frame.FrameInstance$FrameAccess.READ_WRITE:Lcom/oracle/truffle/api/frame/FrameInstance$FrameAccess;
            invokeinterface com.oracle.truffle.api.frame.FrameInstance.getFrame:(Lcom/oracle/truffle/api/frame/FrameInstance$FrameAccess;)Lcom/oracle/truffle/api/frame/Frame;
            astore 3 /* readWrite */
        start local 3 // com.oracle.truffle.api.frame.Frame readWrite
         2: .line 189
            aload 2 /* frameInstance */
            getstatic com.oracle.truffle.api.frame.FrameInstance$FrameAccess.MATERIALIZE:Lcom/oracle/truffle/api/frame/FrameInstance$FrameAccess;
            invokeinterface com.oracle.truffle.api.frame.FrameInstance.getFrame:(Lcom/oracle/truffle/api/frame/FrameInstance$FrameAccess;)Lcom/oracle/truffle/api/frame/Frame;
            astore 4 /* materialized */
        start local 4 // com.oracle.truffle.api.frame.Frame materialized
         3: .line 191
            new java.lang.StringBuilder
            dup
            ldc "Really materialized: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 4 /* materialized */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            aload 4 /* materialized */
            instanceof com.oracle.truffle.api.frame.MaterializedFrame
            invokestatic org.junit.Assert.assertTrue:(Ljava/lang/String;Z)V
         4: .line 192
            ldc "It's my frame"
            aload 1 /* frame */
            aload 3 /* readWrite */
            invokestatic org.junit.Assert.assertEquals:(Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
         5: .line 193
            aload 0 /* this */
            areturn
        end local 4 // com.oracle.truffle.api.frame.Frame materialized
        end local 3 // com.oracle.truffle.api.frame.Frame readWrite
        end local 2 // com.oracle.truffle.api.frame.FrameInstance frameInstance
        end local 1 // com.oracle.truffle.api.frame.VirtualFrame frame
        end local 0 // com.oracle.truffle.api.test.FrameTest$1FrameRootNode this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    6     0           this  Lcom/oracle/truffle/api/test/FrameTest$1FrameRootNode;
            0    6     1          frame  Lcom/oracle/truffle/api/frame/VirtualFrame;
            1    6     2  frameInstance  Lcom/oracle/truffle/api/frame/FrameInstance;
            2    6     3      readWrite  Lcom/oracle/truffle/api/frame/Frame;
            3    6     4   materialized  Lcom/oracle/truffle/api/frame/Frame;
    MethodParameters:
       Name  Flags
      frame  
}
SourceFile: "FrameTest.java"
EnclosingMethod: com.oracle.truffle.api.test.FrameTest.framesCanBeMaterialized:()V
NestHost: com.oracle.truffle.api.test.FrameTest
InnerClasses:
  public final FrameAccess = com.oracle.truffle.api.frame.FrameInstance$FrameAccess of com.oracle.truffle.api.frame.FrameInstance
  FrameRootNode = com.oracle.truffle.api.test.FrameTest$1FrameRootNode