char scratch[64 /* big enough for test_data and more_test_data */] = {0};
  StringPiece result;
  status = read_file->Read(0, test_data.size() + more_test_data.size(), &result,
                           scratch);
  EXPECT_PRED2(UnimplementedOrReturnsCode, status, Code::OK);
  EXPECT_EQ(test_data + more_test_data, result);
  EXPECT_EQ(
      read_file->Read(test_data.size(), more_test_data.size(), &result, scratch)