static std::string double_to_string_helper(double speed)
{
    std::string str = (formatter() << std::fixed << std::setprecision(2) << speed).str();

    str.erase ( str.find_last_not_of('0') + 1, std::string::npos );
    str.erase ( str.find_last_not_of('.') + 1, std::string::npos );

    return str;
}