docs: protected void releaseConnection(Connection connection) throws SQLException {
  		ConnectionHandle handle = (ConnectionHandle)connection;
  
  		// hook calls
  		if (handle.getConnectionHook() != null){
  			handle.getConnectionHook().onCheckIn(handle);
  		}
  
  		// release immediately or place it in a queue so that another thread will eventually close it. If we're shutting down,
  		// close off the connection right away because the helper threads have gone away.
  		if (!this.poolShuttingDown){
  			internalReleaseConnection(handle);
  		}
  	}