docstr: Skip these tests if a mongo client is not running.
docstr_tok: ["Skip","these","tests","if","a","mongo","client","is","not","running","."]
code: def setUp(self):
      """
      Skip these tests if a mongo client is not running.
      """
      if not self.has_mongo_connection:
          self.skipTest("Unable to connect to mongo database.")
  
imports: from unittest import TestCase
  from chatterbot.storage import MongoDatabaseAdapter
  from chatterbot.conversation import Statement
label_desc: Use image node_id 2 for calling the MongoAdapterTestCase obj's underlying member method code with example usage: obj.setUp() without return types