code: function isEventDraggable(event) {
  		var source = event.source || {};
  		return firstDefined(
  				event.startEditable,
  				source.startEditable,
  				opt('eventStartEditable'),
  				event.editable,
  				source.editable,
  				opt('editable')
  			)
  			&& !opt('disableDragging'); // deprecated
  	}
docs: /* Event Editable Boolean Calculations
  ------------------------------------------------------------------------------