代码逻辑的疑问

[miss1997yuan]

if not self.use_rejection_sampling:
alias_edges = {}
for edge in G.edges():
alias_edges[edge] = self.get_alias_edge(edge[0], edge[1])
self.alias_edges = alias_edges
这是walk.py里面根据前一个节点t和当前节点v动态计算概率的代码，但为什么要放在if not self.use_rejection_sampling:这个条件下，不用负采样也应该有这个计算，然后更新alias_edges吧