https://www.graalvm.org/ 
public interface com.oracle.svm.truffle.nfi.LibFFI$ClosureData extends org.graalvm.word.PointerBase
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.oracle.svm.truffle.nfi.LibFFI$ClosureData
  super_class: java.lang.Object
{
  public abstract com.oracle.svm.truffle.nfi.libffi.LibFFI$ffi_closure ffiClosure();
    descriptor: ()Lcom/oracle/svm/truffle/nfi/libffi/LibFFI$ffi_closure;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    RuntimeVisibleAnnotations: 
      org.graalvm.nativeimage.c.struct.CFieldAddress()

  public abstract com.oracle.svm.truffle.nfi.LibFFI$NativeClosureHandle nativeClosureHandle();
    descriptor: ()Lcom/oracle/svm/truffle/nfi/LibFFI$NativeClosureHandle;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    RuntimeVisibleAnnotations: 
      org.graalvm.nativeimage.c.struct.CField()

  public abstract void setNativeClosureHandle(com.oracle.svm.truffle.nfi.LibFFI$NativeClosureHandle);
    descriptor: (Lcom/oracle/svm/truffle/nfi/LibFFI$NativeClosureHandle;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    RuntimeVisibleAnnotations: 
      org.graalvm.nativeimage.c.struct.CField(value = "nativeClosureHandle")
    MethodParameters:
        Name  Flags
      handle  

  public abstract org.graalvm.nativeimage.Isolate isolate();
    descriptor: ()Lorg/graalvm/nativeimage/Isolate;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    RuntimeVisibleAnnotations: 
      org.graalvm.nativeimage.c.struct.CField()

  public abstract void setIsolate(org.graalvm.nativeimage.Isolate);
    descriptor: (Lorg/graalvm/nativeimage/Isolate;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    RuntimeVisibleAnnotations: 
      org.graalvm.nativeimage.c.struct.CField(value = "isolate")
    MethodParameters:
         Name  Flags
      isolate  
}
SourceFile: "LibFFI.java"
NestHost: com.oracle.svm.truffle.nfi.LibFFI
InnerClasses:
  public abstract ClosureData = com.oracle.svm.truffle.nfi.LibFFI$ClosureData of com.oracle.svm.truffle.nfi.LibFFI
  abstract NativeClosureHandle = com.oracle.svm.truffle.nfi.LibFFI$NativeClosureHandle of com.oracle.svm.truffle.nfi.LibFFI
  public abstract ffi_closure = com.oracle.svm.truffle.nfi.libffi.LibFFI$ffi_closure of com.oracle.svm.truffle.nfi.libffi.LibFFI
    RuntimeVisibleAnnotations: 
      org.graalvm.nativeimage.c.CContext(value = Lcom/oracle/svm/truffle/nfi/libffi/LibFFIHeaderDirectives;)
      org.graalvm.nativeimage.c.struct.CStruct(value = "svm_closure_data")