return Multisets.linearTimeSizeImpl(this);
    }

    @Override
    public void clear() {
      throw new UnsupportedOperationException();
    }

    @Override
    public int count(@Nullable Object element) {
      for (Entry<E> entry : entrySet()) {
        if (Objects.equal(entry.getElement(), element)) {
          return entry.getCount();
        }
      }
      return 0;
    }

        final JsonRequestParams params = new JsonRequestParams(request, fessConfig);
        try {
            response.setContentType("application/x-ndjson; charset=UTF-8");
            final long count = searchHelper.scrollSearch(params, doc -> {
                buf.setLength(0);
                buf.append('{');
                boolean first2 = true;

	if objectAPI == nil {
		return
	}

	vars := mux.Vars(r)
	count, err := strconv.Atoi(vars["count"])
	if err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

	chEntries, err := listServerConfigHistory(ctx, objectAPI, true, count)
	if err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

    require(keepAliveDuration > 0L) { "keepAliveDuration <= 0: $keepAliveDuration" }
  }

  fun idleConnectionCount(): Int {
    return connections.count {
      it.withLock { it.calls.isEmpty() }
    }
  }

  fun connectionCount(): Int {
    return connections.size
  }

  /**

        authMethod = null;
        InputStream errorStream = connection.getErrorStream();
        if (errorStream != null && errorStream.available() != 0) {
            int count;
            byte[] buf = new byte[1024];
            while ((count = errorStream.read(buf, 0, 1024)) != -1);
        }
        String authHeader;
        if (response == HTTP_UNAUTHORIZED) {
            authHeader = "WWW-Authenticate";

      Thread.sleep(250)
      backend.shutdown()
      return@schedule -1L
    }

    assertThat(queue.idleLatch().await(500L, TimeUnit.MILLISECONDS)).isTrue()
    assertThat(queue.idleLatch().count).isEqualTo(0)
  }

  }

  @Override
  public Set<E> edgesConnecting(N node) {
    return new MultiEdgesConnecting<E>(incidentEdgeMap, node) {
      @Override
      public int size() {
        return adjacentNodesMultiset().count(node);
      }
    };
  }

  @Override
  @CheckForNull
  public N removeInEdge(E edge, boolean isSelfLoop) {
    if (!isSelfLoop) {
      return removeOutEdge(edge);
    }
    return null;
  }

	defer cancel()
	resp, err := client.Get(timeoutCtx, key)
	if err != nil {
		etcdLogOnceIf(ctx, err, "etcd-retrieve-keys")
		return nil, etcdErrToErr(err, client.Endpoints())
	}
	if resp.Count == 0 {
		return nil, errConfigNotFound
	}
	for _, ev := range resp.Kvs {
		if string(ev.Key) == key {
			return ev.Value, nil
		}
	}
	return nil, errConfigNotFound

var ErrAlreadyLocked = errors.New("file already locked")

// RLockedFile represents a read locked file, implements a special
// closer which only closes the associated *os.File when the ref count.
// has reached zero, i.e when all the readers have given up their locks.
type RLockedFile struct {
	*LockedFile
	mutex sync.Mutex
	refs  int // Holds read lock refs.
}

		// Check if index.
		if strings.HasPrefix(name, "_") {
			idx, err := strconv.Atoi(strings.TrimPrefix(name, "_"))
			if err != nil {
				return nil, fmt.Errorf("column %v not found", name)
			}
			// The position count starts at 1.
			idx--
			if idx >= len(r.csvRecord) || idx < 0 {
				// If field index > number of columns, return null
				return sql.FromNull(), nil
			}
			return sql.FromBytes([]byte(r.csvRecord[idx])), nil
		}