private static String getDoubledFinalConsonantPastParticiple(String verb) {
    String pastParticiple = generateHeuristicDoubledFinalConsonantPastParticiple(verb);
    if (pastParticiple != null) return pastParticiple;
    if (DOUBLED_FINAL_CONSONANTS.contains(verb)) return verb + verb.charAt(verb.length() - 1) + "ed";
    for (String prefix : PREFIXES) {
      if (verb.startsWith(prefix) && DOUBLED_FINAL_CONSONANTS.contains(verb.substring(prefix.length()))) {
        return verb + verb.charAt(verb.length() - 1) + "ed";
      }
    }
    return null;
  }
private static String getDoubledFinalConsonantPastParticiple(String verb)