inspect

# File activesupport/lib/active_support/duration.rb, line 66
    def inspect #:nodoc:
      consolidated = parts.inject(::Hash.new(0)) { |h,part| h[part.first] += part.last; h }
      [:years, :months, :days, :minutes, :seconds].map do |length|
        n = consolidated[length]
        "#{n} #{n == 1 ? length.to_s.singularize : length.to_s}" if n.nonzero?
      end.compact.to_sentence
    end