code: def lock_excl(self, timeout='default'):
          
          timeout = self.timeout if timeout == 'default' else timeout
          timeout = self._cleanup_timeout(timeout)
          self.visalib.lock(self.session, constants.AccessModes.exclusive_lock, timeout, None)
docs: Establish an exclusive lock to the resource.
  
          :param timeout: Absolute time period (in milliseconds) that a resource
                          waits to get unlocked by the locking session before
                          returning an error. (Defaults to self.timeout)