https://openjdk.java.net/ 
public interface sun.jvm.hotspot.runtime.PerfMemory$PerfDataEntryVisitor
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.jvm.hotspot.runtime.PerfMemory$PerfDataEntryVisitor
  super_class: java.lang.Object
{
  public abstract boolean visit(sun.jvm.hotspot.runtime.PerfDataEntry);
    descriptor: (Lsun/jvm/hotspot/runtime/PerfDataEntry;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
      Name  Flags
      pde   
}
SourceFile: "PerfMemory.java"
NestHost: sun.jvm.hotspot.runtime.PerfMemory
InnerClasses:
  public abstract PerfDataEntryVisitor = sun.jvm.hotspot.runtime.PerfMemory$PerfDataEntryVisitor of sun.jvm.hotspot.runtime.PerfMemory