code: func (l Logs) Filter(whiteset stringset.Set) Logs {
  	newLogs := make(Logs)
  	for repo, commits := range l {
  		if whiteset.Has(repo) {
  			newLogs[repo] = commits
  		}
  	}
  	return newLogs
  }
docs: // Filter filters out repositories from the Logs which are not in the whitelist
  // and returns a new Logs.