Function IOBluetoothL2CAPChannelRegisterForChannelCloseNotification 

pub unsafe extern "C-unwind" fn IOBluetoothL2CAPChannelRegisterForChannelCloseNotification(
    channel: &IOBluetoothL2CAPChannelRef,
    callback: IOBluetoothUserNotificationCallback,
    in_ref_con: *mut c_void,
) -> Option<CFRetained<IOBluetoothUserNotificationRef>>

👎Deprecated: renamed to IOBluetoothL2CAPChannelRef::register_for_channel_close_notification

Available on crate features IOBluetoothUserLib and objc2-core-foundation only.