// Expects classNames to be an object mapping feature-bit -> className
export default function featureClassNames(stateObj, classNames) {
  if (!stateObj || !stateObj.attributes.supported_features) return '';

  const features = stateObj.attributes.supported_features;

  return Object.keys(classNames).map(feature => (
    (features & feature) !== 0 ? classNames[feature] : ''
  )).filter(attr => attr !== '').join(' ');
}