# File lib/oauth2/strategy/assertion.rb, line 51
      def build_request(params)
        assertion = build_assertion(params)
        {:grant_type     => "assertion", 
         :assertion_type => "urn:ietf:params:oauth:grant-type:jwt-bearer",
         :assertion      => assertion,
         :scope          => params[:scope]
        }.merge(client_params)
      end