# File lib/sprockets/base.rb, line 64
    def digest
      # Compute the initial digest using the implementation class. The
      # Sprockets release version and custom environment version are
      # mixed in. So any new releases will affect all your assets.
      @digest ||= digest_class.new.update(VERSION).update(version.to_s)

      # Returned a dupped copy so the caller can safely mutate it with `.update`
      @digest.dup
    end