code = (code * 31) + previousMods.hashCode();
code = (code * 31) + leftPrevMods.hashCode(); code = (code * 31) + rightPrevMods.hashCode();
  public int hashCode() {    int code = label.hashCode();    code = (code * 31) + headWord.hashCode();    if (leftSubcat != null)      code = (code * 31) + leftSubcat.hashCode();    if (rightSubcat != null)      code = (code * 31) + rightSubcat.hashCode();    if (headChild != null)      code = (code * 31) + headChild.label().hashCode();    code = (code * 31) + previousMods.hashCode();    code = (code << 1) | (stop ? 1 : 0);    code = (code << 1) | (containsVerb ? 1 : 0);    return code;  }