code: def _inject_specs(self, specs):
      
      if not specs:
        return
  
      logger.debug('Injecting specs to %s: %s', self, specs)
      with self._resolve_context():
        thts, = self._scheduler.product_request(TransitiveHydratedTargets,
                                                [specs])
  
      self._index(thts.closure)
  
      for hydrated_target in thts.roots:
        yield hydrated_target.address
docs: Injects targets into the graph for the given `Specs` object.
  
      Yields the resulting addresses.