Function Hello1

env/internal/runtime_ext_registry_test.cc:49–52

using ::cel::test::StringValueIs;

Value Hello1(const StringValue& input, const Function::InvokeContext& context) {
  return StringValue::From("Hello, old " + input.ToString() + "!",
                           context.arena());
}

Value Hello2(const StringValue& input, const Function::InvokeContext& context) {
  return StringValue::From("Hello, new " + input.ToString() + "!",