hist_entry__append_callchain
ret = hist_entry__append_callchain(he, sample);
ret = hist_entry__append_callchain(he, sample);
int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample);
return hist_entry__append_callchain(he, sample);
hist_entry__append_callchain(he, sample);
err = hist_entry__append_callchain(he, iter->sample);