update_ri_cache (Gem::DocManager)

    # File lib/rubygems/doc_manager.rb, line 64
      def self.update_ri_cache
        load_rdoc rescue return

        return unless defined? RDoc::VERSION # RDoc 1 does not have VERSION

        require 'rdoc/ri/driver'

        options = {
          :use_cache => true,
          :use_system => true,
          :use_site => true,
          :use_home => true,
          :use_gems => true,
          :formatter => RDoc::RI::Formatter,
        }

        driver = RDoc::RI::Driver.new(options).class_cache
      end