private static void Free(IntPtr subtransport)
            {
                SmartSubtransport t = GCHandle.FromIntPtr(Marshal.ReadIntPtr(subtransport, GitSmartSubtransport.GCHandleOffset)).Target as SmartSubtransport;

                if (null != t)
                {
                    try
                    {
                        t.Dispose();
                    }
                    catch (Exception ex)
                    {
                        Proxy.git_error_set_str(GitErrorCategory.Net, ex);
                    }
                }
            }