private <V> Collection<V> filterByType(Map<String, ?> entries, Class<V> clazz) {
        return entries.values().stream()
                .filter(e -> clazz.isAssignableFrom(e.getClass()))
                .map(clazz::cast)
                .collect(toSet());
    }
Clear the cached {@link #map}, forcing a reload from disk on next read.
gateway/engine/filesystem/src/main/java/io/apiman/gateway/engine/filesystem/LocalFileRegistry.java