Function CheckRange

internal/overflow.cc:52–56

    absl::ToInt64Seconds(MaxTimestamp() - absl::UnixEpoch());

absl::Status CheckRange(bool valid_expression,
                        absl::string_view error_message) {
  return valid_expression ? absl::OkStatus()
                          : absl::OutOfRangeError(error_message);
}

absl::Status CheckArgument(bool valid_expression,
                           absl::string_view error_message) {