What is the type signature of the main exported function?

The main exported function getPort has the following type signature [index.d.ts:L66]:

export default function getPort(options?: Options): Promise<number>;

This function:

• Accepts an optional Options parameter
• Returns a Promise that resolves to a number (the available TCP port)

The Options type is defined in [index.d.ts:L3-L65] and includes several optional properties:

• port: A preferred port or iterable of preferred ports
• exclude: Ports that should not be returned
• reserve: Whether to lock the port for the process lifetime (default: false)
• host: The specific host to check port availability on

FOLLOW_UPS:

• What does the reserve option do exactly?
• How does the exclude option work?
• Can you show an example with multiple preferred ports?