code: function() {
      var numArgs = arguments.length;
  
      if (!numArgs) {
        return this.unique();
      }
  
      var result = xorBase(this, arguments[0]);
  
      for (var i = 1; i < numArgs; i++) {
        result = xorBase(result, arguments[i]);
      }
  
      return result;
    }
docs: Finds the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference)
  of the array and the input array(s).
  
  @function Array#xor
  @param {...Array} arrays - A variable number of arrays.
  @returns {Array} The new array of values.
  
  @example
  [1, 2].xor([4, 2]);
  // -> [1, 4]
  
  [1, 2, 5].xor([2, 3, 5], [3, 4, 5]);
  // -> [1, 4, 5]
  // Explanation:
  // [1, 2, 5] ⊕ [2, 3, 5] ⊕ [3, 4, 5] = [1, 4, 5]