https://www.graalvm.org/ 
abstract class com.oracle.truffle.nfi.CallSignatureNode extends com.oracle.truffle.api.nodes.Node
  minor version: 0
  major version: 59
  flags: flags: (0x0420) ACC_SUPER, ACC_ABSTRACT
  this_class: com.oracle.truffle.nfi.CallSignatureNode
  super_class: com.oracle.truffle.api.nodes.Node
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.nfi.CallSignatureNode this
         0: .line 67
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.nodes.Node.<init>:()V
            return
        end local 0 // com.oracle.truffle.nfi.CallSignatureNode this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/nfi/CallSignatureNode;

  abstract java.lang.Object execute(com.oracle.truffle.nfi.NFISignature, java.lang.Object, java.lang.Object[]);
    descriptor: (Lcom/oracle/truffle/nfi/NFISignature;Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0400) ACC_ABSTRACT
    Exceptions:
      throws com.oracle.truffle.api.interop.ArityException, com.oracle.truffle.api.interop.UnsupportedTypeException, com.oracle.truffle.api.interop.UnsupportedMessageException
    MethodParameters:
           Name  Flags
      signature  
      function   
      args       

  static com.oracle.truffle.nfi.CallSignatureNode createOptimizedCall(com.oracle.truffle.nfi.NFIType$TypeCachedState, com.oracle.truffle.nfi.NFISignature$ArgsCachedState);
    descriptor: (Lcom/oracle/truffle/nfi/NFIType$TypeCachedState;Lcom/oracle/truffle/nfi/NFISignature$ArgsCachedState;)Lcom/oracle/truffle/nfi/CallSignatureNode;
    flags: (0x0008) ACC_STATIC
    Code:
      stack=3, locals=2, args_size=2
         0: .line 115
            new java.lang.Error
            dup
            ldc "Unresolved compilation problem: \n\tOptimizedCallSignatureNodeGen cannot be resolved\n"
            invokespecial java.lang.Error.<init>:(Ljava/lang/String;)V
            athrow
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    MethodParameters:
           Name  Flags
      retType    
      argsState  

  static com.oracle.truffle.nfi.CallSignatureNode createOptimizedClosure(com.oracle.truffle.nfi.NFIType$TypeCachedState, com.oracle.truffle.nfi.NFISignature$ArgsCachedState);
    descriptor: (Lcom/oracle/truffle/nfi/NFIType$TypeCachedState;Lcom/oracle/truffle/nfi/NFISignature$ArgsCachedState;)Lcom/oracle/truffle/nfi/CallSignatureNode;
    flags: (0x0008) ACC_STATIC
    Code:
      stack=3, locals=2, args_size=2
         0: .line 119
            new java.lang.Error
            dup
            ldc "Unresolved compilation problem: \n\tOptimizedCallClosureNodeGen cannot be resolved\n"
            invokespecial java.lang.Error.<init>:(Ljava/lang/String;)V
            athrow
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    MethodParameters:
           Name  Flags
      retType    
      argsState  
}
SourceFile: "CallSignatureNode.java"
NestMembers:
  com.oracle.truffle.nfi.CallSignatureNode$CachedCallSignatureNode  com.oracle.truffle.nfi.CallSignatureNode$CallSignatureRootNode  com.oracle.truffle.nfi.CallSignatureNode$OptimizedCallClosureNode  com.oracle.truffle.nfi.CallSignatureNode$OptimizedCallSignatureNode
InnerClasses:
  abstract CachedCallSignatureNode = com.oracle.truffle.nfi.CallSignatureNode$CachedCallSignatureNode of com.oracle.truffle.nfi.CallSignatureNode
  final CallSignatureRootNode = com.oracle.truffle.nfi.CallSignatureNode$CallSignatureRootNode of com.oracle.truffle.nfi.CallSignatureNode
  abstract OptimizedCallClosureNode = com.oracle.truffle.nfi.CallSignatureNode$OptimizedCallClosureNode of com.oracle.truffle.nfi.CallSignatureNode
  abstract OptimizedCallSignatureNode = com.oracle.truffle.nfi.CallSignatureNode$OptimizedCallSignatureNode of com.oracle.truffle.nfi.CallSignatureNode
  final ArgsCachedState = com.oracle.truffle.nfi.NFISignature$ArgsCachedState of com.oracle.truffle.nfi.NFISignature
  abstract TypeCachedState = com.oracle.truffle.nfi.NFIType$TypeCachedState of com.oracle.truffle.nfi.NFIType