anchor.diff:  /// library.
   library encrypted_moor;
   
  +// this file should be kept in sync with moor_flutter/lib/moor_flutter.dart
  +
   import 'dart:async';
  +import 'dart:io';
   import 'package:meta/meta.dart';
   import 'package:path/path.dart';
   import 'package:moor/moor.dart';
   import 'package:moor/backends.dart';
   import 'package:sqflite/sqflite.dart' as s;
  +
  +/// Signature of a function that runs when a database doesn't exist on file.
  +/// This can be useful to, for instance, load the database from an asset if it
  +/// doesn't exist.
  +typedef DatabaseCreator = FutureOr<void> Function(File file);
   
   class _SqfliteDelegate extends DatabaseDelegate with _SqfliteExecutor {
     int _loadedSchemaVersion;
  
positive.code:       onUpgrade: (db, from, to) {
          _loadedSchemaVersion = from;
        },
      );
    }
  }
  
  
negative.code:       resolvedPath = path;
      }
  
      final file = File(resolvedPath);
      if (creator != null && !await file.exists()) {
        await creator(file);
      }
  
      // default value when no migration happened
      _loadedSchemaVersion = db.schemaVersion;
  
  