* `allocations.size() < allocationLimit` then new streams can be created on this connection.
   */
  internal var allocationLimit = 1
    private set

  /** Current calls carried by this connection. */
  val calls = mutableListOf<Reference<RealCall>>()

  /** Timestamp when `allocations.size()` reached zero. Also assigned upon initial connection. */

        key == this.key -> next // Subtract this!

        else -> {
          val nextMinusKey = next.plus(key, null)
          when {
            nextMinusKey === next -> this // Same as the following line, but with fewer allocations.
            else -> LinkedTags(this.key, this.value, nextMinusKey)
          }
        }
      }

    // Return a new `Tags` that maps `key` to `value`.
    return when {

   * toIndex} exclusive. This is equivalent to {@code
   * Collections.rotate(Shorts.asList(array).subList(fromIndex, toIndex), distance)}, but is
   * considerably faster and avoids allocations and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @throws IndexOutOfBoundsException if {@code fromIndex < 0}, {@code toIndex > array.length}, or

   * toIndex} exclusive. This is equivalent to {@code
   * Collections.rotate(Shorts.asList(array).subList(fromIndex, toIndex), distance)}, but is
   * considerably faster and avoids allocations and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @throws IndexOutOfBoundsException if {@code fromIndex < 0}, {@code toIndex > array.length}, or

      eventListener.callFailed(this, result!!)
    } else {
      eventListener.callEnd(this)
    }
    return result
  }

  /**
   * Remove this call from the connection's list of allocations. Returns a socket that the caller
   * should close.
   */
  internal fun releaseConnectionNoEvents(): Socket? {
    val connection = this.connection!!
    connection.assertLockHeld()

   * toIndex} exclusive. This is equivalent to {@code
   * Collections.rotate(Ints.asList(array).subList(fromIndex, toIndex), distance)}, but is
   * considerably faster and avoids allocations and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @throws IndexOutOfBoundsException if {@code fromIndex < 0}, {@code toIndex > array.length}, or

   * toIndex} exclusive. This is equivalent to {@code
   * Collections.rotate(Floats.asList(array).subList(fromIndex, toIndex), distance)}, but is
   * considerably faster and avoids allocations and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @throws IndexOutOfBoundsException if {@code fromIndex < 0}, {@code toIndex > array.length}, or

     * sizing; if the Set uses different equality semantics, it might contain duplicates according
     * to equals(), and we will deduplicate those properly, albeit at some cost in allocations.
     */
    int expectedSize =
        elements instanceof Set ? array.length : estimatedSizeForUnknownDuplication(array.length);
    return fromArrayWithExpectedSize(array, expectedSize);
  }

  /**

   * toIndex} exclusive. This is equivalent to {@code
   * Collections.rotate(Bytes.asList(array).subList(fromIndex, toIndex), distance)}, but is
   * considerably faster and avoids allocations and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @throws IndexOutOfBoundsException if {@code fromIndex < 0}, {@code toIndex > array.length}, or

   * toIndex} exclusive. This is equivalent to {@code
   * Collections.rotate(Longs.asList(array).subList(fromIndex, toIndex), distance)}, but is
   * considerably faster and avoids allocations and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @throws IndexOutOfBoundsException if {@code fromIndex < 0}, {@code toIndex > array.length}, or