What am I doing wrong?

import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

public class MainActivity extends FragmentActivity implements
        ActionBar.TabListener {

    // Some code has been omitted for brevity!

    public ActionBar mActionBar;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mActionBar = getActionBar();
        mActionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        PagerAdapter pagerAdapter = new PagerAdapter(getSupportFragmentManager());

        // Some code omitted for brevity...

        for (int i = 0; i < pagerAdapter.getCount(); i++) {
            ActionBar.Tab tab = mActionBar.newTab();
            tab.setText(PagerAdapter.getPageTitle(i));
            tab.setTabListener(this);

            /*
             * Add your code here to set the text!
             */

            mActionBar.addTab(tab);
        }
    }

    // These listener methods are intentionally blank
    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { }

    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { }
}