in e2e-examples/gcs/dummy_server/main.cc [151:160]
static std::string LoadStringFromFile(std::string path) {
std::ifstream file(path);
if (!file.is_open()) {
std::cout << "Failed to open " << path << std::endl;
abort();
}
std::stringstream sstr;
sstr << file.rdbuf();
return sstr.str();
}