library/src/main/java/net/rdrei/android/dirchooser/DirectoryChooserActivity.java
void setupActionBar() {
        // there might not be an ActionBar, for example when started in Theme.Holo.Dialog.NoActionBar theme
        @SuppressLint("AppCompatMethod") final ActionBar actionBar = getActionBar();
        if (actionBar != null) {
            actionBar.setDisplayHomeAsUpEnabled(true);
        }
    }
void setupActionBar() {
        // there might not be an ActionBar, for example when started in Theme.Holo.Dialog.NoActionBar theme
        @SuppressLint("AppCompatMethod") final ActionBar actionBar = getActionBar();
        if (actionBar != null) {
            actionBar.setDisplayHomeAsUpEnabled(true);
        }
    }
/* package