code: def set_references(self, references):
          
          descriptor = Descriptor(None, "counters", None, None, None)
          counters = references.get_optional(descriptor)
          for counter in counters:
              if isinstance(counter, ICounters):
                  self._counters.append(counter)
docs: Sets references to dependent components.
  
          :param references: references to locate the component dependencies.