def _check(self,requirement,expected):
     result = _constrain(
         self.i,
         tuple(parse_requirements(requirement))[0]
         )
     self.failUnless(isinstance(result,Requirement))
     compare(expected,str(result))
 def test_setuptools_distribute(self):
     compare(
         Requirement.parse('distribute'),
         _constrain(self.Installer,Requirement.parse('setuptools'))
         )