return done(null, result);
} else if (isFallbackCompletionFunction(this.customCompletionFunction)) {
current,
argv,
(onCompleted = done) =>
this.defaultCompletion(args, argv, current, onCompleted),
completions => {
done(null, completions);
}
} else {
return (this.customCompletionFunction as AsyncCompletionFunction)(