Mark xfail for Py2.6 for a test of set-like behaviour with dict methods
Mark xfail for Py2.6 for a test of set-like behaviour with dict methods

QuLogic/python-future,krischer/python-future,krischer/python-future,QuLogic/python-future,PythonCharmers/python-future,michaelpacer/python-future,michaelpacer/python-future,PythonCharmers/python-future