Provides attributes for the given port. For ports that your extension doesn't know about, simply
return undefined. For example, if providePortAttributes
is called with ports 3000 but your
extension doesn't know anything about 3000 you should return undefined.
Optional
commandOptional
pid?: numberA cancellation token that indicates the result is no longer needed.
A provider of port attributes. Port attributes are used to determine what action should be taken when a port is discovered.