@Nullable
    public byte[] getManufacturerSpecificData(int manufacturerId) {
        return manufacturerSpecificData.get(manufacturerId);
    }
Returns the manufacturer specific data associated with the manufacturer id. Returns
{@code null} if the {@code manufacturerId} is not found.
rxandroidble/src/main/java/com/polidea/rxandroidble2/internal/scan/ScanRecordImplCompat.java