code: function concat() {
        var length = arguments.length;
        if (!length) {
          return [];
        }
        var args = Array(length - 1),
            array = arguments[0],
            index = length;
  
        while (index--) {
          args[index - 1] = arguments[index];
        }
        return arrayPush(isArray(array) ? copyArray(array) : [array], baseFlatten(args, 1));
      }
docs: Creates a new array concatenating `array` with any additional arrays
  and/or values.
  
  @static
  @memberOf _
  @since 4.0.0
  @category Array
  @param {Array} array The array to concatenate.
  @param {...*} [values] The values to concatenate.
  @returns {Array} Returns the new concatenated array.
  @example
  
  var array = [1];
  var other = _.concat(array, 2, [3], [[4]]);
  
  console.log(other);
  // => [1, 2, 3, [4]]
  
  console.log(array);
  // => [1]