Can I use GPLv2 code of mercurial for implementing bzr's code?

[INADA Naoki]

I'm implementing i18n code on lp:~songofacandy/bzr/from-hg.
I reused mercurial's per-paragraph i18n code.
And I want to reuse mercurial's MBTextWrapper_ too.

_MBTextWrapper:
https://bitbucket.org/mirror/mercurial/src/d8ba6fb2ce15/mercurial/util.py#cl-1128

Mercurial and Bazaar are licensed under GPLv2. So I think I can reuse
mercurial's code for bzr. Is it collect? Does the Bazaar's single copyright
holder policy blocks other GPL code?

-- 
INADA Naoki  <songofacandy at gmail.com>