@Test
  public void testAddWithGoogleCorpAccount() {
    AccountIndex index = index(AccountDb.GOOGLE_CORP_ACCOUNT_NAME, null);
    // No existing account yet
    assertThat(accountDb.addWillOverwriteExistingSeedFor(index)).isFalse();

    addSomeRecordsWithNullIssuer(); // Adds a Google Internal 2Factor account
    assertThat(accountDb.addWillOverwriteExistingSeedFor(index)).isTrue();
    validateAccountRecord(index, SECRET, OtpType.HOTP, 0, true);

    // Try re-adding the account, which should overwrite despite the null issuer
    accountDb.add(AccountDb.GOOGLE_CORP_ACCOUNT_NAME, SECRET2, OtpType.HOTP, 0, null, null);
    validateAccountRecord(index, SECRET2, OtpType.HOTP, 0, true);

    assertThat(accountDb.getAccounts()).hasSize(TEST_ACCOUNTS_WITH_NULL_ISSUER.length);
  }
A list of {@link TestAccount}s that all have issuers.
javatests/com/google/android/apps/authenticator/otp/AccountDbTest.java