Thank you very much for your response, but perhaps I should explain the reason for asking this question so that, if possible, you may guide me further.
Perhaps you have already read the question I raised in my previous message with the title of Implementing Widgets for Selecting Nodes of Type Segment and Beam. In general, I want to familiarize myself with the process of developing modules in 3DSlicer. Therefore, I want to learn how I can develop the functionality of widgets so that I can select specific nodes from the Data module and process them. For example, with one widget, I should be able to select only nodes of type Segment, with another widget, only nodes of type Model, and with yet another widget, only nodes of type Beam.
Based on this, the roadmap I set for myself was to first create a UI that contains a widget of type qMRMLSegmentSelectorWidget to select only nodes of type Segment. The reason I chose this node is that I found out this widget is part of the Slicer [MRML Widgets] in Widget Box of Qt Designer, and it seems to have been specifically added to Qt Designer by the 3D Slicer development team for module implementation. (At this point, I also had a problem, as I couldn’t find other widgets in the list that, based on their names, I could guess might be useful for selecting nodes of specific types.)
By selecting this particular widget, I expected that the related Python file would be much shorter so I could analyze and understand its components, and ultimately develop its function so that it would select only nodes of type Segment from the Data module. As I mentioned in my message, the Python file that was generated was default and contains 403 lines.
Best regards.
Shahrokh