code: def run_command(self, command, arg=None, is_eval=False, member_id=None):
          
          logger.debug("run_command({command}, {arg}, {is_eval}, {member_id})".format(**locals()))
          mode = is_eval and 'eval' or 'command'
          hostname = None
          if isinstance(member_id, int):
              hostname = self.member_id_to_host(member_id)
          result = getattr(self.connection(hostname=hostname).admin, mode)(command, arg)
          logger.debug("command result: {result}".format(result=result))
          return result
docs: run command on replica set
          if member_id is specified command will be execute on this server
          if member_id is not specified command will be execute on the primary
  
          Args:
              command - command string
              arg - command argument
              is_eval - if True execute command as eval
              member_id - member id
  
          return command's result