@NonNull
	public final DisconnectRequest disconnect() {
		return Request.disconnect().setRequestHandler(requestHandler);
	}
Disconnects from the device or cancels the pending connection attempt.
Does nothing if device was not connected.

@return The disconnect request. The completion callback will be called after the device
has disconnected and the connection was closed. If the device was not connected,
the completion callback will be called immediately with device parameter set to null.
ble/src/main/java/no/nordicsemi/android/ble/BleManager.java