Evaluate asynchronous tasks with configurable concurrency

 A queue evaluates zero or more deferred asynchronous tasks with configurable
 concurrency: you control how many tasks run at the same time. When all the
 tasks complete, or an error occurs, the queue passes the results to your await
 callback.
 .
 This library is similar to Async.js’s parallel (when *concurrency* is infinite)
 , series (when *concurrency* is 1), and queue, but features a much smaller
 footprint: as of release 2, d3-queue is about 700 bytes gzipped, compared to
 4,300 for Async.
 .
 Node.js is an event-based server-side JavaScript engine.