'Returns any warning suppressions set for this test. Checks on the
instance first, then the class, then the module, then packages. As
soon as it finds something with a C{suppress} attribute, returns that.
Returns any empty list (i.e. suppress no warnings) if it cannot find
anything. See L{TestCase} docstring for more details.'

def _getSuppress(self):

    return util.acquireAttribute(self._parents, 'suppress', [])
