public List <NodeProgress> GetKnowledgeNodes(int lectureId, int?learnerId)
{
var nodes = _lectureRepository.GetKnowledgeNodes(lectureId);
if (nodes == null)
{
return(null);
}
if (learnerId == null)
{
return(ShowSampleNodes(nodes));
}
//TODO: Check if prerequisites fulfilled.
return(null);
}