code: @Override
      public String[] getObjectHistory(Context context, String PID)
              throws ServerException {
          PID = Server.getPID(PID).toString();
          m_authorizationModule.enforceGetObjectHistory(context, PID);
          DOReader reader =
                  m_manager.getReader(Server.USE_DEFINITIVE_STORE, context, PID);
  
          return reader.getObjectHistory(PID);
      }
docs: <p>
  Gets the change history of an object by returning a list of timestamps
  that correspond to modification dates of components. This currently
  includes changes to datastreams and disseminators.
  </p>
  
  @param context
  The context of this request.
  @param PID
  The persistent identifier of the digitla object.
  @return An Array containing the list of timestamps indicating when
  changes were made to the object.
  @throws ServerException
  If any type of error occurred fulfilling the request.