trust_root_valid (OpenID::Server::CheckIDRequest)

    # File lib/openid/server.rb, line 572
          def trust_root_valid
            if !@trust_root
              return true
            end

            tr = TrustRoot::TrustRoot.parse(@trust_root)
            if !tr
              raise MalformedTrustRoot.new(@message, @trust_root)
            end

            if @return_to
              return tr.validate_url(@return_to)
            else
              return true
            end
          end