code: function isDraggingFiles(event) {
  	// If `event.dataTransfer` is not available then `event.target.files` fallback is used.
  	if (!event.dataTransfer) {
  		return true
  	}
  	// https://developer.mozilla.org/en-US/docs/Web/API/DataTransfer/types
  	// https://developer.mozilla.org/en-US/docs/Web/API/HTML_Drag_and_Drop_API/Recommended_drag_types#file
  	return Array.prototype.some.call(
  		event.dataTransfer.types,
  		type => type === 'Files' || type === 'application/x-moz-file'
  	)
  }
docs: Copied from: https://github.com/react-dropzone/react-dropzone/blob/master/src/utils/index.js