private async Task writeUpkHeader()
{
writer.Seek(0);
writer.WriteUInt32(Signature);
writer.WriteUInt16(Version);
writer.WriteUInt16(Licensee);
writer.WriteInt32(BuilderSize);
await Group.WriteBuffer(writer, 0);
writer.WriteUInt32(Flags);
writer.WriteInt32(NameTable.Count);
writer.WriteInt32(BuilderNameTableOffset);
writer.WriteInt32(ExportTable.Count);
writer.WriteInt32(BuilderExportTableOffset);
writer.WriteInt32(ImportTable.Count);
writer.WriteInt32(BuilderImportTableOffset);
writer.WriteInt32(BuilderDependsTableOffset);
writer.WriteBytes(Guid);
writer.WriteInt32(GenerationTable.Count);
await writeGenerationTable();
writer.WriteUInt32(EngineVersion);
writer.WriteUInt32(CookerVersion);
writer.WriteUInt32(CompressionFlags);
writer.WriteInt32(CompressedChunks.Count);
writer.WriteUInt32(Unknown1);
writer.WriteUInt32(Unknown2);
}