get (HTTPClient::SSPINegotiateAuth)

    # File lib/httpclient/auth.rb, line 471
        def get(req)
          return nil unless SSPIEnabled
          target_uri = req.header.request_uri
          domain_uri, param = @challenge.find { |uri, v|
            Util.uri_part_of(target_uri, uri)
          }
          return nil unless param
          state = param[:state]
          authenticator = param[:authenticator]
          authphrase = param[:authphrase]
          case state
          when :init
            authenticator = param[:authenticator] = Win32::SSPI::NegotiateAuth.new
            return authenticator.get_initial_token
          when :response
            @challenge.delete(domain_uri)
            return authenticator.complete_authentication(authphrase)
          end
          nil
        end