code: function isSubSet (aTestArray, aRefArray) {
  		function isOutsideSet(sTestValue) {
  			return aRefArray.indexOf(sTestValue) < 0; // value is not part of the reference set
  		}
  		return aTestArray && aRefArray && !aTestArray.some(isOutsideSet);
  	}
docs: Utility function that checks if the content of an array
  is a subset of the content of a second (reference) array