Walker?

https://www.pygit2.org/commit_log.html describes a Walker object, but does not explain how to get one or how to use it. Are we to infer that the the iterator produced by the call to Repository.walk() immediately above is an object of type Walker? When I debug that seems to be the case.

For example, if heads is a list of heads and w a Walker, will

for h in heads:
    w.push(h)
    for cmt in w:
        do_stuff(cmt)

call do_stuff exactly once (i.e., the walker remembers and ignores commits already visited on later calls) for each commit in my repository that is reachable from any head?

从 https://www.pygit2.org/commit_log.html 上的 commit_log 文档和 Repository.walk() 的描述开始。明确如何获取和使用 Walker，包括迭代是否会在重复调用 push 之间保留已访问的 commit。完成的标准是：读者无需自行推断，页面就能说明示例的行为。