def [](connection_name)
      class_name = connection_name.to_s.split('_').map { |s| s.capitalize }.join

      begin
        Coolio::Connections.const_get class_name
      rescue NameError
        raise NameError, "No connection type registered for #{connection_name.inspect}"
      end
    end
def [](connection_name)
      class_name = connection_name.to_s.split('_').map { |s| s.capitalize }.join

      begin
        Coolio::Connections.const_get class_name
      rescue NameError
        raise NameError, "No connection type registered for #{connection_name.inspect}"
      end
    end
Look up a connection class by its name