@Nullable
	public Integer getUserID() {
		return userID;
	}
Returns the measurement unit, one of {@link #UNIT_mmHg} or {@link #UNIT_kPa}.
To convert to proper unit, use {@link #toMmHg(float, int)} or {@link #toKPa(float, int)}.

@return Unit of systolic, diastolic and mean arterial pressure.
ble-common/src/main/java/no/nordicsemi/android/ble/common/callback/bps/BloodPressureMeasurementResponse.java