code: def remove(self, locator):
          
          if locator == None:
              return None
  
          self._lock.acquire()
          try:
              for reference in reversed(self._references):
                  if reference.match(locator):
                      self._references.remove(reference)
                      return reference.get_component()
          finally:
              self._lock.release()
          
          return None
docs: Removes a previously added reference that matches specified locator.
          If many references match the locator, it removes only the first one.
          When all references shall be removed, use [[removeAll]] method instead.
  
          :param locator: a locator to remove reference
  
          :return: the removed component reference.