mongo-repository.cs

public abstract class MongoRepository<TEntity> : IRepository<TEntity> 
    where TEntity : EntityBase
{
    protected abstract IMongoCollection<TEntity> Collection { get; }

    public MongoRepository(MongoDataContext dataContext)
    {

    }
    public virtual async Task AddNewAsync(TEntity entity)
    {
        await Collection.InsertOneAsync(entity);
    }

    // [..]
}