function isTouch() {
  try {
    document.createEvent('TouchEvent')
    return true
  } catch (e) {
    return false
  }
}
String representation of component state for styling with class names.

 Expects an array of strings OR a string/object pair:
 - className(['comp', 'comp-arg', 'comp-arg-2'])
   @returns 'react-images__comp react-images__comp-arg react-images__comp-arg-2'
 - className('comp', { some: true, state: false })
   @returns 'react-images__comp react-images__comp--some'