NODEJS SDK 3.1 - async cluster.close()?

Why is cluster.close() is an Async function, whereas there is no await in the function ?
cluster.js code

Welcome to the group @linqFR, close is async for interface reasons

Thank you @AV25242

My thought was that, as we can experience quite sometimes “cluster was closed”/“parent closed has been closed”, maybe any ‘await’ could be needed within cluster.closed().