code: function sampleSize(collection, n) {
          var index = -1, result = toArray(collection), length = result.length, lastIndex = length - 1;
          n = baseClamp(toInteger(n), 0, length);
          while (++index < n) {
            var rand = baseRandom(index, lastIndex), value = result[rand];
            result[rand] = result[index];
            result[index] = value;
          }
          result.length = n;
          return result;
        }
docs: Gets `n` random elements at unique keys from `collection` up to the
  size of `collection`.
  
  @static
  @memberOf _
  @category Collection
  @param {Array|Object} collection The collection to sample.
  @param {number} [n=0] The number of elements to sample.
  @returns {Array} Returns the random elements.
  @example
  
  _.sampleSize([1, 2, 3], 2);
  // => [3, 1]
  
  _.sampleSize([1, 2, 3], 4);
  // => [2, 3, 1]