# File lib/rubygems/specification.rb, line 639
    def add_dependency(gem, *requirements)
      requirements = if requirements.empty? then
                       Gem::Requirement.default
                     else
                       requirements.flatten
                     end

      unless gem.respond_to?(:name) && gem.respond_to?(:version_requirements)
        gem = Dependency.new(gem, requirements)
      end

      dependencies << gem
    end