anchor.diff:  }
   
   @DataClassName('Category')
  -class Categories extends Table {
  -  IntColumn get id => integer().autoIncrement()();
  +class Categories extends Table with AutoIncrement {
     TextColumn get description =>
         text().named('desc').customConstraint('NOT NULL UNIQUE')();
   }
  
positive.code: 
  part 'todos.g.dart';
  
  @DataClassName('TodoEntry')
  class TodosTable extends Table {
    @override
    String get tableName => 'todos';
  
    IntColumn get id => integer().autoIncrement()();
    TextColumn get title => text().withLength(min: 4, max: 16).nullable()();
    TextColumn get content => text()();
    @JsonKey('target_date')
  
negative.code:   TextColumn get custom => text().map(const CustomConverter())();
  }
  
  class PureDefaults extends Table with AutoIncrement {
    TextColumn get txt => text().nullable()();
  }
  
  