return all_schemes;
}

static std::vector<std::string> GetSchemes() {
  static std::vector<std::string>* schemes = GetSchemesFromUserOrEnv();
  return *schemes;
}

INSTANTIATE_TEST_SUITE_P(ModularFileSystem, ModularFileSystemTest,
                         ::testing::ValuesIn(GetSchemes()));

// Loads a shared object implementing filesystem functionality.
static bool LoadDSO(const std::string& dso) {