A trait which allows for customization of connections.
fn on_acquire(&self, conn: &mut C) -> Result<(), E>
Called with connections immediately after they are returned from
The default implementation simply returns
If this method returns an error, the connection will be discarded.
fn on_release(&self, conn: C)
Called with connections when they are removed from the pool.
The connections may be broken (as reported by
has_broken), or have simply timed out.
The default implementation does nothing.