requirement

# File lib/rubygems/dependency.rb, line 98
  def requirement
    return @requirement if defined?(@requirement) and @requirement

    # @version_requirements and @version_requirement are legacy ivar
    # names, and supported here because older gems need to keep
    # working and Dependency doesn't implement marshal_dump and
    # marshal_load. In a happier world, this would be an
    # attr_accessor. The horrifying instance_variable_get you see
    # below is also the legacy of some old restructurings.
    #
    # Note also that because of backwards compatibility (loading new
    # gems in an old RubyGems installation), we can't add explicit
    # marshaling to this class until we want to make a big
    # break. Maybe 2.0.
    #
    # Children, define explicit marshal and unmarshal behavior for
    # public classes. Marshal formats are part of your public API.

    if defined?(@version_requirement) && @version_requirement
      version = @version_requirement.instance_variable_get :@version
      @version_requirement  = nil
      @version_requirements = Gem::Requirement.new version
    end

    @requirement = @version_requirements if defined?(@version_requirements)
  end