public IList<SectionDefinition> GetSections()

{
  //Use the SelectedVariableProfile to get the sections currently in the TOC
  //via its associated volume
  var volume = voxelLayer.SelectedVariableProfile.Volume;

  var section = volume.GetSections().FirstOrDefault();
  var section2 = volume.GetSections().First(sec => sec.ID == my_section_id);
}

{
  // Note: call within QueuedTask.Run()
  {
    if (voxelLayer.Visualization != VoxelVisualization.Surface)
      voxelLayer.SetVisualization(VoxelVisualization.Surface);
    voxelLayer.SetSectionContainerExpanded(true);
    voxelLayer.SetSectionContainerVisibility(true);

    //Use the SelectedVariableProfile to get the sections currently in the TOC
    //via its associated volume
    var volume = voxelLayer.SelectedVariableProfile.Volume;
    var sections = volume.GetSections();
  }
}

{
  // Note: call within QueuedTask.Run()
  {
    if (voxelLayer.Visualization != VoxelVisualization.Surface)
      voxelLayer.SetVisualization(VoxelVisualization.Surface);
    voxelLayer.SetSectionContainerExpanded(true);
    voxelLayer.SetSectionContainerVisibility(true);

    //Use the SelectedVariableProfile to get the sections
    //via its associated volume
    var volume = voxelLayer.SelectedVariableProfile.Volume;

    foreach (var section in volume.GetSections())
    {
      //set each normal to 45.0 orientation and tilt
      section.Normal = voxelLayer.GetNormal(45.0, 45.0);
      //apply the change
      volume.UpdateSection(section);
    }
  }
}

{
  // Note: call within QueuedTask.Run()
  {
    if (voxelLayer.Visualization != VoxelVisualization.Surface)
      voxelLayer.SetVisualization(VoxelVisualization.Surface);
    voxelLayer.SetSectionContainerExpanded(true);
    voxelLayer.SetSectionContainerVisibility(true);

    //Use the SelectedVariableProfile to get the sections
    //via its associated volume
    var volume = voxelLayer.SelectedVariableProfile.Volume;
    var sections = volume.GetSections().Where(s => !s.IsVisible);

    //Make them all visible
    foreach (var section in sections)
    {
      section.IsVisible = true;
      //apply the change
      volume.UpdateSection(section);
    }
  }
}