dotcmis - SessionFactory not found -

i'm starting using cmis. i'm trying first sample apache site work (https://chemistry.apache.org/dotnet/getting-started-with-dotcmis.html) compiler not accept sessionfactory. doing wrong?

using system; using system.collections.generic; using system.linq; using dotcmis; using dotcmis.client;  namespace cmis_testandexplore { class program  {     static void main(string[] args)     {         dictionary<string, string> parameters = new dictionary<string, string>();          parameters[sessionparameter.bindingtype] = bindingtype.atompub;         parameters[sessionparameter.atompuburl] = "http://<http://localhost:8081/inmemory/atom";         parameters[sessionparameter.user] = "test";         parameters[sessionparameter.password] = "";          sessionfactory factory = sessionfactory.newinstance();         isession session = factory.getrepositories(parameters)[0].createsession();     } } 

}

it turns out missing using statement. had add:

using dotcmis.client.impl;