* simultaneously adopted and removed.
   */
  private val connections = ConcurrentLinkedQueue<RealConnection>()

  init {
    // Put a floor on the keep alive duration, otherwise cleanup will spin loop.
    require(keepAliveDuration > 0L) { "keepAliveDuration <= 0: $keepAliveDuration" }
  }

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

  abstract @Nullable C leastValueAbove(DiscreteDomain<C> domain);

  abstract @Nullable C greatestValueBelow(DiscreteDomain<C> domain);

  /*
   * The canonical form is a BelowValue cut whenever possible, otherwise ABOVE_ALL, or
   * (only in the case of types that are unbounded below) BELOW_ALL.
   */
  Cut<C> canonical(DiscreteDomain<C> domain) {
    return this;
  }

  // note: overridden by {BELOW,ABOVE}_ALL
  @Override

"external only" mode, then the final link will be an external one.
Otherwise the link will be an internal one.

The linking directives are used according to the kind of final link
used.

In internal mode, cmd/link itself processes all the host object files, in
particular foo.cgo2.o. To do so, it uses the cgo_import_dynamic and
cgo_dynamic_linker directives to learn that the otherwise undefined

   *
   * <p>By default, the map uses {@link Equivalence#identity} to determine key equality when {@link
   * #weakKeys} is specified, and {@link Equivalence#equals()} otherwise. The only place this is
   * used is in {@link Interners.WeakInterner}.
   */
  @CanIgnoreReturnValue
  @GwtIncompatible // To be supported
  MapMaker keyEquivalence(Equivalence<Object> equivalence) {

    `https://google.com`, which doesn't follow the SPDY/3.1 spec!
 *  Fix: Always configure NPN headers. This fixes connectivity to
    `https://facebook.com` when SPDY and HTTP/2 are both disabled. Otherwise an
    unexpected NPN response is received and OkHttp crashes.
 *  Fix: Write continuation frames when HPACK data is larger than 16383 bytes.
 *  Fix: Don't drop uncaught exceptions thrown in async calls.

   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableSet#of()} instead. If {@code
   * E} is an {@link Enum} type, use {@link EnumSet#noneOf} instead. Otherwise, strongly consider
   * using a {@code LinkedHashSet} instead, at the cost of increased memory footprint, to get
   * deterministic iteration behavior.
   *

  abstract @Nullable C leastValueAbove(DiscreteDomain<C> domain);

  abstract @Nullable C greatestValueBelow(DiscreteDomain<C> domain);

  /*
   * The canonical form is a BelowValue cut whenever possible, otherwise ABOVE_ALL, or
   * (only in the case of types that are unbounded below) BELOW_ALL.
   */
  Cut<C> canonical(DiscreteDomain<C> domain) {
    return this;
  }

  // note: overridden by {BELOW,ABOVE}_ALL
  @Override

    }
    return null;
  }

  /**
   * Performs a search over the children of a node to find the child with the given label.
   *
   * @return the index of the child node if found, or -1 otherwise.
   */
  private int findChild(int firstChild, int numChildren, String label) {
    int low = firstChild;
    int high = firstChild + numChildren - 1;

    while (low <= high) {

                    holder.count++;
                    return Thread.currentThread().getStackTrace().length;
                  },
                  directExecutor()));
        } else {
          // Otherwise, schedule a task on directExecutor
          unused =
              serializer.submit(
                  () -> {
                    holder.count++;
                    return null;
                  },

        gitWrapper.updateTags(upstream);
    }

    /**
     * This methods checks the supplied version and answers {@code false} if the fetching of git
     * tags can be skipped, or {@code true} otherwise.
     * <p>
     * The first version in a minor series will never have any preceding versions, so there's no
     * need to fetch tags and examine the repository state in the past. This applies when the