[libredwg] DWG Handles

[gagan]

I was just skimming through the autocad dxf
specifications and found
that it needs a handle for objects like LAYER, DIMSTYLE, BLOCK_HEADER,
VPORT, APPID etc but in libredwg structs for LAYER,
DIMSTYLE, BLOCK_HEADER, VPORT, APPID I am unable to find handles.
There are two handles in each struct namingly xdicobjhandle and
null_handle and AFAIK, both of them don't give the desired handle
values. I am checking with a (converted copy of example.dwg) dxf file
generated by draftsight. Can anyone please help me on this ??
--
Thanks
Gagan

-- 
Thanks
Gaganjyot