ROOT 5.28 unbound method in ROOT.vector (python)

Python 2.6.5 (r265:79063, Jun 4 2010, 21:42:56) [GCC 4.1.2 20080704 (Red Hat 4.1.2-48)] on linux2 Type "help", "copyright", "credits" or "license" for more information.
>>> import ROOT
>>> a = ROOT.vector("int")
>>> a

<class 'ROOT.vector<int,allocator<int> >'>
>>> a.push_back(1)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: void vector<int,allocator<int> >::push_back(const int& x) =>

    unbound method vector<int,allocator<int> >::push_back must be called with a vector<int,allocator<int> > instance as first argument Received on Wed Dec 22 2010 - 21:21:04 CET