# File lib/active_support/core_ext/array/grouping.rb, line 23
        def in_groups_of(number, fill_with = nil, &block)
          require 'enumerator'
          collection = dup
          collection << fill_with until collection.size.modulo(number).zero? unless fill_with == false
          grouped_collection = [] unless block_given?
          collection.each_slice(number) do |group|
            block_given? ? yield(group) : grouped_collection << group
          end
          grouped_collection unless block_given?
        end