'Volume_type extra specs are found successfully.'

@mock.patch.object(context, 'get_admin_context')
@mock.patch.object(volume_types, 'get_volume_type')
def test_get_volume_type_extra_spec(self, m_get_volume_type, m_get_admin_context):

    vol = VOLUME.copy()
    vol['volume_type_id'] = 1
    volume_type = {'extra_specs': {'override:test_key': 'test_value'}}
    m_get_admin_context.return_value = None
    m_get_volume_type.return_value = volume_type
    result = self.driver._get_volume_type_extra_spec(vol, 'test_key')
    m_get_admin_context.assert_called_with()
    m_get_volume_type.assert_called_with(None, vol['volume_type_id'])
    self.assertEqual('test_value', result)
