def METHOD_NAME(self):
    cluster = new_cluster(
        resource_tags=dict(tag2='value2a', tag3='value3')
    )
    self.assertEqual('mocked cluster', cluster)
    coiled_mock = sys.modules['coiled']
    self.assertEqual('my_image-1-2-3', coiled_mock.software_name)
    self.assertEqual(
        {'account': 'my_coiled_account',
         'compute_purchase_option': 'spot_with_fallback',
         'environ': None,
         'n_workers': 4,
         'name': None,
         'region': 'eu-central-1',
         'shutdown_on_close': True,
         'software': 'my_image-1-2-3',
         'tags': {'cost-center': 'unknown',
                  'creator': 'auto',
                  'environment': 'dev',
                  'purpose': 'xcube dask cluster',
                  'user': os.environ.get('USER',
                                         os.environ.get('USERNAME')),
                  'tag1': 'value1',
                  'tag2': 'value2a',
                  'tag3': 'value3'},
         'use_best_zone': True},
        coiled_mock.cluster_kwargs)