private async Task ReadInternalAsync(Stream stream) { Signature = await GifHelpers.ReadStringAsync(stream, 3).ConfigureAwait(false); if (Signature != "GIF") { throw GifHelpers.InvalidSignatureException(Signature); } Version = await GifHelpers.ReadStringAsync(stream, 3).ConfigureAwait(false); if (Version != "87a" && Version != "89a") { throw GifHelpers.UnsupportedVersionException(Version); } LogicalScreenDescriptor = await GifLogicalScreenDescriptor.ReadAsync(stream).ConfigureAwait(false); }