迁移数据库的问题Room android

Question

我遇到Android Room问题。我正在尝试从预先填充的SQLITE数据库迁移。

    class IpMap(Table, BaseModel):
TypeError: Error when calling the metaclass bases
    metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases

代码行：

import android.arch.persistence.db.SupportSQLiteDatabase;
import android.arch.persistence.room.Database;
import android.arch.persistence.room.Room;
import android.arch.persistence.room.RoomDatabase;
import android.arch.persistence.room.migration.Migration;

@Database(entities = {Attributes.class}, version = 2)

public abstract class AppDatabase extends RoomDatabase {

    private static AppDatabase INSTANCE;

    public abstract AttributesDao attributesDao();

    Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "Attributes.db")
        .addMigrations(MIGRATION_1_2).build();

    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
        @Override
        public void migrate(SupportSQLiteDatabase database) {
        }
    };

}

犯了很多错误。知道是什么原因引起的吗？

错误：Build Errors