task.js

const queue = new TaskQueue(2); // Limit concurrency to 2 tasks

const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

// Add tasks to the queue
queue.add(() => sleep(1000).then(() => console.log("Task 1 completed")));
queue.add(() => sleep(500).then(() => console.log("Task 2 completed")));
queue.add(() => sleep(300).then(() => console.log("Task 3 completed")));
queue.add(() => sleep(400).then(() => console.log("Task 4 completed")));

// Expected output (timing may vary):
// Task 1 completed (after ~1000ms)
// Task 2 completed (after ~1000ms)
// Task 3 completed (after ~1300ms)
// Task 4 completed (after ~1400ms)