code: function ( array1, array2 ) {
  		var result = [];
  
  		array.each( array1, function ( i ) {
  			if ( !array.contains( array2, i ) ) {
  				array.add( result, i );
  			}
  		});
  
  		array.each( array2, function ( i ) {
  			if ( !array.contains( array1, i ) ) {
  				array.add( result, i );
  			}
  		});
  
  		return result;
  	}
docs: Finds the difference between array1 and array2
  
  @method diff
  @param  {Array} array1 Source Array
  @param  {Array} array2 Comparison Array
  @return {Array}        Array of the differences