    # File lib/chef/knife/cookbook_site_install.rb, line 109
          def parse_name_args!
            if name_args.empty?
              ui.error("please specify a cookbook to download and install")
              exit 1
            elsif name_args.size > 1
              ui.error("Installing multiple cookbooks at once is not supported")
              exit 1
            else
              name_args.first
            end
          end