aas_test_engines/test_cases/v3_0/api.py: test_include_concept_descriptions empty results error

[Frosty2500]

In test_include_concept_descriptions it is not checked if the data is empty, which leads to the error

    _assert('conceptDescriptions' in data, 'contains conceptDescriptions', Level.WARNING)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: argument of type 'NoneType' is not iterable

when testing our server.
This is fixed by adding the following assertion.

_assert(data is not None, 'Result is not empty')

So when I use this method

def test_include_concept_descriptions(self):
    """
    Invoke with includeConceptDescriptions    """    request = generate_one_valid(self.operation, self.sample_cache, {'includeConceptDescriptions': True})
    data = _invoke_and_decode(request, self.conf, True)
    _assert(data is not None, 'Result is not empty')
    _assert('conceptDescriptions' in data, 'contains conceptDescriptions', Level.WARNING)

it is possible to test our server.