Method closer

src/kernels/raw/session/rawSocket.node.ts:72–78

(closable: { close(): void })

        // When the socket is completed / disposed, close all the event
        // listeners and shutdown the socket
        const closer = (closable: { close(): void }) => {
            try {
                closable.close();
            } catch (ex) {
                logger.error(`Error during socket shutdown`, ex);
            }
        };
        closer(this.channels.control);
        closer(this.channels.iopub);
        closer(this.channels.shell);