public static FieldDeclaration add_Field(this TypeDeclaration typeDeclaration, FieldDeclaration fieldDeclaration)
 {
     if (typeDeclaration.notNull() && fieldDeclaration.notNull() && typeDeclaration.Children.notNull())
     {
         //var insertPosition = typeDeclaration.Children.Count;
         var insertPosition = 0;  // fields are OK to go at the top
         typeDeclaration.Children.Insert(insertPosition, fieldDeclaration);
     }
     return fieldDeclaration;
 }