internal class SomeDisposableClass : IDisposable
    {
        private readonly System.IO.Stream _managedResource;

        private bool _disposed;

        public SomeDisposableClass(System.IO.Stream managedResource)
        {
            _managedResource = managedResource;
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if(_disposed)
            {
                return;
            }

            if(disposing)
            {
                _managedResource?.Dispose();
            }

            _disposed = true;
        }
    }

internal sealed class DerivedDisposableClass : SomeDisposableClass
    {
        private readonly System.IO.Stream _anotherResource;

        public DerivedDisposableClass(System.IO.Stream managedResource, System.IO.Stream anotherResource)
            : base(managedResource)
        {
            _anotherResource = anotherResource;
        }

        protected override void Dispose(bool disposing)
        {
            _anotherResource?.Dispose();

            base.Dispose(disposing);
        }
    }