'``RootCredential.initialize`` writes a PEM file to the
specified path.'

def test_written_keypair_exists(self):

    path = FilePath(self.mktemp())
    path.makedirs()
    RootCredential.initialize(path, 'mycluster')
    self.assertEqual((True, True), (path.child(AUTHORITY_CERTIFICATE_FILENAME).exists(), path.child(AUTHORITY_KEY_FILENAME).exists()))
