+ * Finds 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
+
+ /**
+ * Gets worker index.