# File lib/rdoc/markup/document.rb, line 97
  def merge other
    if empty? then
      @parts = other.parts
      return self
    end

    other.parts.each do |other_part|
      self.parts.delete_if do |self_part|
        self_part.file and self_part.file == other_part.file
      end

      self.parts << other_part
    end

    self
  end