'Verifies that strcred.makeChecker(\'sshkey\') returns an object
that implements the L{ICredentialsChecker} interface.'

def test_isChecker(self):

    sshChecker = strcred.makeChecker('sshkey')
    self.assertTrue(checkers.ICredentialsChecker.providedBy(sshChecker))
    self.assertIn(credentials.ISSHPrivateKey, sshChecker.credentialInterfaces)
