@Test
public void returnNullWhenAccountIsDeleted() {

    //asserting that account exists.
    stubSavedAccount(EXPECTED_ACCOUNT);
    assertEquals(EXPECTED_ACCOUNT, googleAccountsManager.getLastSelectedAccountIfValid());
    //removing the account simulates the deletion of the account via Google account settings.
    removeAccounts();
    assertEquals(googleAccountsManager.getLastSelectedAccountIfValid(), "");
    assertNull(savedAccount);
}