/// <summary>
/// Builds features tree.
/// This operatio is performed when control is created.
/// </summary>
void BuildFeaturesTree()
{
_featureNodes.Clear();
_featuresSet = FeaturesHelper.CreateFeaturesSet();
foreach (FeatureNode node in _featuresSet.Nodes)
{
AddFeatureNode(null, node);
}
tvFeatures.ExpandAll();
}