code: def get_causal_sink_nodes(graph: BELGraph, func) -> Set[BaseEntity]:
      
      return {
          node
          for node in graph
          if node.function == func and is_causal_sink(graph, node)
      }
docs: Returns a set of all ABUNDANCE nodes that have an causal out-degree of 0.
  
      This likely means that the knowledge assembly is incomplete, or there is a curation error.