ensure_authenticated (Merb::AuthenticatedHelper)

    # File lib/merb-auth-core/authenticated_helper.rb, line 31
        def ensure_authenticated(*strategies)
          session.authenticate!(request, params, *strategies) unless session.authenticated?
          auth = session.authentication
          if auth.halted?
            self.headers.merge!(auth.headers)
            self.status  = auth.status
            throw :halt, auth.body
          end
          session.user
        end