title: Problem using android.accounts Authenticator
body: <p>I'm new to the android.accounts apis, and now I'm trying to do something with them but a seemly dummy problem occurs...<br>
  I`ve created an Authenticator for my app but did not yet implement the abstract methods. The icon of it successfully appears in the system Add a Account window, and I know that when I click it, the method addAccount in the Authenticator will be invoked.  </p>
  
  <p>Now I wish to do some simple thing in this method, and write codes below:  </p>
  
  <pre><code>    @Override
  public Bundle addAccount(AccountAuthenticatorResponse response,
          String accountType, String authTokenType, String[] requiredFeatures,
          Bundle options) {
  
      Log.d(LOG_TAG, "RRAuthenticator add account... ");
      String accountName = "example@example.com";
      Account account = new Account(accountName, accountType);
      String password = "example_password";
      AccountManager manager = AccountManager.get(context);
      manager.addAccountExplicitly(account, password, null);
  
      Bundle bundle = new Bundle();
      bundle.putString(AccountManager.KEY_ACCOUNT_NAME, accountName);
      bundle.putString(AccountManager.KEY_ACCOUNT_TYPE, accountType);
      bundle.putString(AccountManager.KEY_AUTHTOKEN, "example_authtoken");
      return bundle;
  }
  </code></pre>
  
  <p>I've seen the demo of SampleSyncAdapter, and make moves like it. But I practice using these APIs by directly adding an account.
  But system crashed by the line <code>manager.addAccountExplicitly(account, password, null);</code>
  What's wrong with it?</p>
  
  <hr>
  
  <p>Added later:
  Exception in system process. System will crash.
  NullPointerException throw by AccountManager.
  It seems the problem of the addAccountExplicitly method, as I comment this statement no crash happen.</p>