internal static extern int git_diff_blobs( GitObjectSafeHandle oldBlob, GitObjectSafeHandle newBlob, GitDiffOptions options, git_diff_file_cb fileCallback, git_diff_hunk_cb hunkCallback, git_diff_data_cb lineCallback, IntPtr payload);
internal static extern int git_diff_print_patch( DiffListSafeHandle diff, git_diff_data_cb printCallback, IntPtr payload);