@NonNull
	protected final BluetoothGattDescriptor descriptor(@NonNull final UUID uuid,
													   @DescriptorPermissions final int permissions,
													   @Nullable final byte[] initialValue) {
		final BluetoothGattDescriptor descriptor = new BluetoothGattDescriptor(uuid, permissions);
		descriptor.setValue(initialValue);
		return descriptor;
	}
A helper method that creates a descriptor with given UUID and permissions.
Optionally, an initial value may be set.
<p>
The value of the descriptor will NOT be shared between clients. Each client will write
and read its own copy. To create a shared descriptor, use
{@link #sharedDescriptor(UUID, int, byte[])} instead.

@param uuid The characteristic UUID.
@param permissions The bit mask or descriptor permissions. See {@link BluetoothGattCharacteristic}
                   for details.
@param initialValue The optional initial value of the descriptor.
@return The characteristic.
ble/src/main/java/no/nordicsemi/android/ble/BleServerManager.java