IList<DisplayUnitFormat> GetProjectUnitFormats( 
   UnitFormatType unitFormat
)

//Must be on the QueuedTask.Run()

var unit_formats = Enum.GetValues(typeof(UnitFormatType))
                      .OfType<UnitFormatType>().ToList();
System.Diagnostics.Debug.WriteLine("Project units\r\n");

foreach (var unit_format in unit_formats)
{
  var units = DisplayUnitFormats.Instance.GetProjectUnitFormats(unit_format);
  System.Diagnostics.Debug.WriteLine(unit_format.ToString());

  foreach (var display_unit_format in units)
  {
    var line = $"{display_unit_format.DisplayName}, {display_unit_format.UnitCode}";
    System.Diagnostics.Debug.WriteLine(line);
  }
  System.Diagnostics.Debug.WriteLine("");
}

//Must be on the QueuedTask.Run()

//UnitFormatType.Angular, UnitFormatType.Area, UnitFormatType.Distance, 
//UnitFormatType.Direction, UnitFormatType.Location, UnitFormatType.Page
//UnitFormatType.Symbol2D, UnitFormatType.Symbol3D
var units = DisplayUnitFormats.Instance.GetProjectUnitFormats(UnitFormatType.Distance);

//UnitFormatType.Angular, UnitFormatType.Area, UnitFormatType.Distance, 
//UnitFormatType.Direction, UnitFormatType.Location
var angle_units = DisplayUnitFormats.Instance.GetProjectUnitFormats(UnitFormatType.Angular);

//Edit the display name of each unit - append the abbreviation
foreach (var unit in angle_units)
{
  unit.DisplayName = $"{unit.DisplayName} ({unit.Abbreviation})";
}
//apply the changes to the units and set the default to be the first entry
DisplayUnitFormats.Instance.SetProjectUnitFormats(angle_units, angle_units.First());

//The project must be saved to persist the changes...