interface IUoW
{
  IDocRepository DocRepository{get;}
  IFileRepository FileRepository{get;}

  SaveChangesAsync ();
}

class DocRepository: IDocRepository
{
  private DbContext _dbContext;
  public DocRepository(DbContext context) {_dbContext = context}
}

class UoW: IUoW
{
  private DbContext _dbContext;
  private IDocRepository _docRepository;
  ... IFileRepository

  public UoW (DbContext dbContext, IDocRepository docRepository) {...}
 
  IDocRepository DocRepository {get {return _docRepository}}
  ... IFileRepository
}