ensure_required_rubygems_version_met

# File lib/rubygems/installer.rb, line 549
  def ensure_required_rubygems_version_met
    if rrgv = spec.required_rubygems_version then
      unless rrgv.satisfied_by? Gem.rubygems_version then
        raise Gem::InstallError,
          "#{spec.name} requires RubyGems version #{rrgv}. " +
          "Try 'gem update --system' to update RubyGems itself."
      end
    end
  end