# File lib/bee_task_default.rb, line 723
      def required(params)
        require 'rubygems'
        require 'rubygems/gem_runner'
        params_desc = {
          :library => { :mandatory => true, :type => :string },
          :message => { :mandatory => true, :type => :string }
        }
        check_parameters(params, params_desc)
        library = params[:library]
        message = params[:message]
        if Gem::RubyGemsVersion < '1.3.0'
          begin
            Gem::activate(library, false)
            available = true
          rescue LoadError
            available = false
          end
        else
          available = Gem::available?(library)
        end
        error message if not available
      end