code: function() {
              var args = slice.call(arguments),
                  array = [],
                  i, ln;
  
              for (i = 0, ln = args.length; i < ln; i++) {
                  array = array.concat(args[i]);
              }
  
              return ExtArray.unique(array);
          }
docs: Merge multiple arrays into one with unique items.
  
  {@link Ext.Array#union} is alias for {@link Ext.Array#merge}
  
  @param {Array} array1
  @param {Array} array2
  @param {Array} etc
  @return {Array} merged