[&env]() { return env->NowSeconds(); });
  // Execute the first read to load the block.
  TF_EXPECT_OK(ReadCache(&cache2, "", 0, 1, &out));
  EXPECT_EQ(calls, 1);
  // Advance the clock by a huge amount and verify that the cached block is
  // used to satisfy the read.
  env->SetNowSeconds(365 * 24 * 60 * 60);  // ~1 year, just for fun.
  TF_EXPECT_OK(ReadCache(&cache2, "", 0, 1, &out));
  EXPECT_EQ(calls, 1);
}

  status = env_->NewRandomAccessFile(filepath, &read_file);
  if (!status.ok())
    GTEST_SKIP() << "NewRandomAccessFile() not supported: " << status;

  char scratch[64 /* must be bigger than test_data */] = {0};
  StringPiece result;
  // read at least 1 byte more than test_data
  status = read_file->Read(0, test_data.size() + 1, &result, scratch);

    return -1;
  }
  int64_t read;
  auto content_length = stream.headers().find("content-length");
  if (content_length == stream.headers().end()) {
    // When we read a file with offset that is bigger than the actual file size.
    // GCS will return an empty header (e.g no `content-length` header). In this
    // case, we will set read to `0` and continue.
    read = 0;