}
    }

    override fun put(element: T) {
      taskRunner.lock.withLock {
        delegate.put(element)
        editCount++
      }
    }

    override fun iterator() = error("unsupported")

    override fun offer(e: T) = error("unsupported")

    override fun peek(): T = error("unsupported")

    override fun offer(
      element: T,
      timeout: Long,
      unit: TimeUnit,