add_dependency_with_type

# File lib/rubygems/specification.rb, line 1546
  def add_dependency_with_type(dependency, type, requirements)
    requirements = if requirements.empty? then
                     Gem::Requirement.default
                   else
                     requirements.flatten
                   end

    unless dependency.respond_to?(:name) &&
           dependency.respond_to?(:requirement)
      dependency = Gem::Dependency.new(dependency.to_s, requirements, type)
    end

    dependencies << dependency
  end