code: function applicable(filepath, info, callback) {
    const q = queue();
    preprocessors.forEach((preprocessor) => {
      q.defer(preprocessor.criteria, filepath, info);
    });
  
    q.awaitAll((err, results) => {
      if (err) return callback(err);
      callback(null, preprocessors.filter((preprocessor, i) => {
        return !!results[i];
      }));
    });
  }
docs: A function that checks a file against each preprocessor's criteria callback returns only those applicable to this file