# File lib/diff/lcs/hunk.rb, line 101
  def diff(format)
    case format
    when :old
      old_diff
    when :unified
      unified_diff
    when :context
      context_diff
    when :ed
      self
    when :reverse_ed, :ed_finish
      ed_diff(format)
    else
      raise "Unknown diff format #{format}."
    end
  end