'A top-level dictionary with any arbitrary key containing another
dictionary with an "image" key is detected as a valid fig format.
Note that "valid fig-format" does not necessarily translate to
"valid configuration", it just means that the suppled configuration
will be treated and parsed as fig-format rather than flocker-format.
A valid fig-style configuration is defined as:
Overall application configuration is of type dictionary, containing
one or more keys which each contain a further dictionary, which
contain exactly one "image" key or "build" key and does not contain
any invalid keys.'

def test_valid_fig_config_detected_on_image(self):

    config = {u'postgres': {u'image': u'sample/postgres'}}
    parser = FigConfiguration(config)
    self.assertTrue(parser.is_valid_format())
