Remove branches from mercurial - svn conversion

[Berkes Adam]

Hi,

Is it possible to completely left out svn branches from the conversion 
(hg convert ...)?
There are possiblities to rename branch, split, remove commits, but I 
cannot find a usable solution to completely skip certain branch 
conversion. It is very important for me because the conversion took 
extremly long, and to strip branches afterward is also enormously slow 
(so altogether - took days).

Any idea would be appreciated,
Adam Berkes