result = {'success': False, 'stats': []}
try:
	mgr = ProductManager()
	r = await mgr.get_usage_stats(filters={
		'group_by': params_kw.get('group_by', 'product_id'),
		'start_date': params_kw.get('start_date', ''),
		'end_date': params_kw.get('end_date', '')
	})
	result = r
except Exception as e:
	result['error'] = str(e)
	debug(format_exc())
return json.dumps(result, ensure_ascii=False, default=str)