private void setDisplayHomeAsUpEnabled(boolean showHomeAsUp) {
            ActionBar actionBar = getActionBar();
            if (actionBar != null) {
                actionBar.setDisplayHomeAsUpEnabled(showHomeAsUp);
            }
        }
Set whether home should be displayed as an "up" affordance.
Set this to true if selecting "home" returns up by a single level in your UI
rather than back to the top level or front page.

@param showHomeAsUp true to show the user that selecting home will return one
                    level up rather than to the top level of the app.
progressfragment-native-sample/src/com/devspark/progressfragment/sample/ProgressActivity.java