When using semsimiam implementation, opaque errors are omitted if no predicates are passed`

[cmungall]

runoak --stacktrace -i semsimian:sqlite:obo:phenio -v termset-similarity MP:0010771 MP:0002169 MP:0005391 MP:0005389 MP:0005367 @ HP:0004325 HP:0000093 MP:0006144 HP:0001254 HP:0001217 HP:0001222 HP:0001248 HP:0001263 HP:0001279

gives

  File "/Users/cjm/repos/ontology-access-kit/src/oaklib/implementations/semsimian/semsimian_implementation.py", line 237, in termset_pairwise_similarity
    semsimian = self._get_semsimian_object(
  File "/Users/cjm/repos/ontology-access-kit/src/oaklib/implementations/semsimian/semsimian_implementation.py", line 88, in _get_semsimian_object
    predicates = tuple(sorted(predicates))
TypeError: 'NoneType' object is not iterable

Minimally it should check for this condition and throw a NotImplemented error with a message explaining that predicates must be selected

or better: semsimian should simply accept empty predicates, meaning use all predicates