code: def get_mongo_version(self):
          
          if self._mongo_version:
              return self._mongo_version
  
          mongo_version = self.read_current_mongo_version()
  
          if not mongo_version:
              mongo_version = self.get_configured_mongo_version()
  
          self._mongo_version = mongo_version
  
          return self._mongo_version
docs: Gets mongo version of the server if it is running. Otherwise return
           version configured in mongoVersion property