* 'host': Specifies a proxy host to be stored in `/etc/apt/apt.conf.d/01proxy`. Valid options: a string containing a hostname. Default: undef.
- * 'port': Specifies a proxy port to be stored in `/etc/apt/apt.conf.d/01proxy`. Valid options: a string containing a port number. Default: '8080'.
+ * 'port': Specifies a proxy port to be stored in `/etc/apt/apt.conf.d/01proxy`. Valid options: an integer containing a port number. Default: 8080.
* 'https': Specifies whether to enable https proxies. Valid options: 'true' and 'false'. Default: 'false'.