code: byte[] loadPersist() {
      // 00       assert: not written yet
      // 01       assert: load-after-delete
      // 10       expected; read
      // 11       assert: load-after-delete
      assert isPersisted();
      try {
        byte[] res = H2O.getPM().load(backend(), this);
        assert !isDeleted();        // Race in user-land: load-after-delete
        return res;
      } catch( IOException ioe ) { throw Log.throwErr(ioe); }
    }
docs: Load some or all of completely persisted Values