+ * Whether the pool is busy or not.
+ *
+ * The pool busyness boolean status.
+ */
+ readonly busy: boolean
+
+ /**
+ * Number of tasks currently concurrently running.
+ */
+ readonly numberOfRunningTasks: number
+
+ /**
+ * Find a free worker based on the number of tasks the worker has applied.
+ *
+ * If a worker is found with `0` running tasks, it is detected as free and returned.
+ *
+ * If no free worker is found, `false` is returned.
+ *
+ * @returns A free worker if there is one, otherwise `false`.
+ */
+ findFreeWorker(): Worker | false
+
+ /**
+ * Get worker index.