Method patch

src/backend/common/Version.hpp:40–40

    constexpr int major() const { return major_; }
    constexpr int minor() const { return minor_; }
    constexpr int patch() const { return patch_; }

    constexpr Version(const int ver_major, const int ver_minor = -1,
                      const int ver_patch = -1) noexcept