@Test
  public void testIsGoogleAccountWithNullIssuer() {
    addSomeRecordsWithNullIssuer();
    assertThat(accountDb.isGoogleAccount(index("1@b.c", null))).isTrue();
    // Note: New accounts with @gmail or @google addresses are no longer assumed to be Google
    // accounts unless they also have the Google issuer
    assertThat(accountDb.isGoogleAccount(index("2@gmail.com", null))).isFalse();
    assertThat(accountDb.isGoogleAccount(index("3@google.com", null))).isFalse();
    assertThat(accountDb.isGoogleAccount(index("4", null))).isTrue();
    assertThat(accountDb.isGoogleAccount(index("5@yahoo.co.uk", null))).isFalse();
    assertThat(accountDb.isGoogleAccount(index("gmail.com", null))).isFalse();
    assertThat(accountDb.isGoogleAccount(index("Google Internal 2Factor", null))).isTrue();
    assertThat(accountDb.isGoogleAccount(index("non-existent account", null))).isFalse();
  }
Note: caller should carefully determine the expected value of {@code isGoogleAccount}, which
is affected by multiple factors.

@param isGoogleAccount is a {@code boolean}, not a {@link Boolean}
javatests/com/google/android/apps/authenticator/otp/AccountDbTest.java