Connection close filter
This is a special connection filter that gets called (if present and active) when a connection gets closed.
The main purpose of this filter type is to clean up anything you may have created during the lifetime of the connection, such as connections to resources.
A typical use of this filter would be to close a database connection established by (for instance) a regular connection filter.
then you could clean up that connection by creating a connection close filter with the following code: