function chunk(array, size, guard) {
	      if (guard ? isIterateeCall(array, size, guard) : size == null) {
	        size = 1;
	      } else {
	        size = nativeMax(nativeFloor(size) || 1, 1);
	      }
	      var index = 0,
	          length = array ? array.length : 0,
	          resIndex = -1,
	          result = Array(nativeCeil(length / size));

	      while (index < length) {
	        result[++resIndex] = baseSlice(array, index, (index += size));
	      }
	      return result;
	    }
Creates an array of elements split into groups the length of `size`.
If `collection` can't be split evenly, the final chunk will be the remaining
elements.

@static
@memberOf _
@category Array
@param {Array} array The array to process.
@param {number} [size=1] The length of each chunk.
@param- {Object} [guard] Enables use as a callback for functions like `_.map`.
@returns {Array} Returns the new array containing chunks.
@example

_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]