https://openjdk.java.net/ 
public interface sun.tools.jconsole.ProxyClient$SnapshotMBeanServerConnection extends javax.management.MBeanServerConnection
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.tools.jconsole.ProxyClient$SnapshotMBeanServerConnection
  super_class: java.lang.Object
{
  public abstract void flush();
    descriptor: ()V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
SourceFile: "ProxyClient.java"
NestHost: sun.tools.jconsole.ProxyClient
InnerClasses:
  public abstract SnapshotMBeanServerConnection = sun.tools.jconsole.ProxyClient$SnapshotMBeanServerConnection of sun.tools.jconsole.ProxyClient