code: function() {
              var returnType, list = [];
              for (var i = 0; i < arguments.length; i++) {
                  var arg = arguments[i];
                  if (isArray(arg.value)) {
                      returnType = returnType || arg.type;
                      arg = arg.value;
                  }
                  list = list.concat(arg);
              }
  
              return newLessList(list, returnType);
          }
docs: ....................................................