https://openjdk.java.net/ 
public interface jdk.internal.access.foreign.UnmapperProxy
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: jdk.internal.access.foreign.UnmapperProxy
  super_class: java.lang.Object
{
  public abstract long address();
    descriptor: ()J
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract java.io.FileDescriptor fileDescriptor();
    descriptor: ()Ljava/io/FileDescriptor;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract boolean isSync();
    descriptor: ()Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract void unmap();
    descriptor: ()V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
SourceFile: "UnmapperProxy.java"