def _find_new_additions(self, candidates) -> None:
        """Find any nodes in the graph that need to be added to the internal
        queue and add them.
        """
        for node in candidates:
            if self.graph.in_degree(node) == 0 and not self._already_known(node):
                self.inner.put((self._scores[node], node))
                self.queued.add(node)
Find any nodes in the graph that need to be added to the internal
        queue and add them.
        
core/dbt/graph/queue.py