public static List<String> parseFlat(final String featureDir, final List<Pair<Pattern, BiFunction<String, String, String>>> parameterMatchers) throws IOException {
        return parseGrouped(featureDir, parameterMatchers).values().stream().flatMap(Collection::stream).collect(Collectors.toList());
    }
Parses features to a {@code List} of Gremlin strings.

@param featureDir The root directory where feature files can be found including subdirectories
@param parameterMatchers list of pattern/functions that will transform a parameter from its Gherkin form to
                         another format triggering that new formatted string to be inserted into the Gremlin
                         itself
gremlin-language/src/main/java/org/apache/tinkerpop/gremlin/language/corpus/FeatureReader.java