assert(matches>=minimumMatches,'Expected to find at least $minimumMatches files with extension ".$extension" in "$workingDirectory", but only found $matches.');
}
Future<String>_getCommitRange()async{
// Using --fork-point is more conservative, and will result in the correct
// fork point, but when running locally, it may return nothing. Git is
// guaranteed to return a (reasonable, but maybe not optimal) result when not
// using --fork-point, so we fall back to that if we can't get a definitive
// fork point. See "git merge-base" documentation for more info.