https://softelvdm.com/Documentation/SftTree%20NET%202%200?Topic=g_api_softelvdm_sfttreenet_dimensionsclass_gapbetweenparts
GapBetweenParts Property, DimensionsClass Class - SftTree/NET 2.0 - Tree Control for Windows Forms
SftTree/NET 2.0 Documentation - Tree Control for Windows Forms