`procRoot` points to the procfs root, e.g. /proc
`sysctl` is the path for the sysctl, e.g. /proc/sys/<sysctl>
`cacheFor` caches the sysctl's value for the given time duration;
`0` disables caching
`procRoot` points to the procfs root, e.g. /proc
`sysctl` is the path for the sysctl, e.g. /proc/sys/<sysctl>
`cacheFor` caches the sysctl's value for the given time duration;
`0` disables caching