new_contents: import unittest
  from biothings_explorer.user_query_dispatcher import SingleEdgeQueryDispatcher
  from .utils import get_apis
  
  class TestSingleHopQuery(unittest.TestCase):
  
      def test_variant2gene(self):
          # test <gene, enableMF, mf>
          seqd = SingleEdgeQueryDispatcher(input_cls='SequenceVariant',
                                           input_id='DBSNP',
                                           output_cls='Gene',
                                           output_id='SYMBOL',
                                           pred='located_in',
                                           values='rs137852559')
          seqd.query()
          self.assertTrue('SHOX' in seqd.G)
          edges = seqd.G['DBSNP:rs137852559']['SHOX']
          self.assertTrue('LitVar API' in get_apis(edges))
subject: add test for litvar