This module allows one to create special connection caches, e.g. by deriving from the official ones
`Inactive connections carry the channel binding
ID as argument. Since 3.8, there is the option of storing an exception
private_data. This may be used by implementations to store
private data together with the file descriptor.
Closes all descriptors known to the cache
A restrictive cache closes connections as soon as there are no pending requests.
This type of cache tries to keep connections as long open as
possible. The consequence is that users are responsible for
closing the descriptors (by calling
close_connection_cache) when the
cache is no longer in use. It is also possible to derive a special
version of the cache from this class, e.g. for closing descriptors
when they are idle for some time.