if和else两个语句在java，Android中执行

Question

我已经制作了一个静态函数来更改片段

/**
 * This will replace fragment with current fragment
 * 
 * @isAddToBackStack if it is true means when you pressback that caller
 *                   fragment will come
 * @bundle If you want to pass any value from one fragment to another
 *         fragment then pass value over here using Bundle
 */

public static int callFragment(Activity mActivity, Fragment mFragment,
        boolean isAddToBackStack, Bundle bundle) {
    FragmentManager fragmentManager = mActivity.getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager
            .beginTransaction();
    if (bundle != null) {
        mFragment.setArguments(bundle);
    }
    fragmentTransaction.replace(R.id.changeFragment, mFragment);
    if (isAddToBackStack) {
        return fragmentTransaction.addToBackStack("").commit(); //----------EXECUTING
    } else {
        return fragmentTransaction.commit(); //----------EXECUTING
    }

}

我通过以下方法调用上面的函数

Constants.callFragment(MainActivity.this,
                        new MyContactFragment(), true, null);

但我已将调试指针放到调试应用程序中，我已经看到了 有时这个if和else两个语句都在执行

if (isAddToBackStack) {
            return fragmentTransaction.addToBackStack("").commit(); //----------EXECUTING
        } else {
            return fragmentTransaction.commit(); //----------EXECUTING
        }

如果有人知道请告诉我我在做什么错误