public BondFieldMappingAttribute(BondField field_, Focus focus_=Focus.None, FieldType fieldType_=FieldType.None, CellColourScheme colourScheme_=CellColourScheme.None)
 {
   Field = field_;
   Focus = focus_;
   FieldType = fieldType_;
   ColourScheme = colourScheme_;
 }
 public static string[] FindColumnsForColourScheme(CellColourScheme scheme_)
 {
   return fieldMappings.Where(x => x.Value.ColourScheme == scheme_).Select(x => x.Key).ToArray();
 }