How to use the threatexchange.forms.ThreatExchangePrivacyGroupForm function in threatexchange

def get_privacy_group_form(request):
    if request.method == "POST" and request.is_ajax():
        initial = request.POST.copy()
        form = forms.ThreatExchangePrivacyGroupForm(initial=initial)
        template = render_to_string("privacy_form.html",
                                    {'privacy_group_form': form})
        result = {'success': True,
                'html': template}
        return HttpResponse(json.dumps(result),
                            content_type="application/json")
    else:
        return render_to_response('error.html',
                                  {'error': "Must be AJAX."},
                                  RequestContext(request))

def __init__(self, *args, **kwargs):
        kwargs.setdefault('label_suffix', ':')
        super(ThreatExchangePrivacyGroupForm, self).__init__(*args, **kwargs)