    # File lib/rubygems/commands/sources_command.rb, line 9
      def initialize
        super 'sources',
              'Manage the sources and cache file RubyGems uses to search for gems'

        add_option '-a', '--add SOURCE_URI', 'Add source' do |value, options|
          options[:add] = value
        end

        add_option '-l', '--list', 'List sources' do |value, options|
          options[:list] = value
        end

        add_option '-r', '--remove SOURCE_URI', 'Remove source' do |value, options|
          options[:remove] = value
        end

        add_option '-c', '--clear-all',
                   'Remove all sources (clear the cache)' do |value, options|
          options[:clear_all] = value
        end

        add_option '-u', '--update', 'Update source cache' do |value, options|
          options[:update] = value
        end
      end