TypeError: undefined is not iterable (cannot read property Symbol(Symbol.iterator))
    at Connection.onMessage (/var/cache/npm/mongodb-4.12.0/lib/cmap/connection.js:177:51)
    at MessageStream.<anonymous> (/var/cache/npm/mongodb-4.12.0/lib/cmap/connection.js:61:60)
    at MessageStream.emit (events.js:400:28)
    at MessageStream.emit (domain.js:475:12)
    at /var/cache/npm/mongodb-4.12.0/lib/cmap/message_stream.js:151:16
    at callbackTrampoline (internal/async_hooks.js:130:17)

        // Get the first orphaned operation description.
        const entry = this[kQueue].entries().next();
        if (entry) {
==>       const [requestId, orphaned]: [number, OperationDescription] = entry.value;
          // If the orphaned operation description exists then set it.
          operationDescription = orphaned;
          // Remove the entry with the bad request id from the queue.
          this[kQueue].delete(requestId);
        }