@Override
  public boolean equals(Object obj) {
    if (this == obj)
      return true;
    if (!super.equals(obj))
      return false;
    if (getClass() != obj.getClass())
      return false;
    PayloadTermQuery other = (PayloadTermQuery) obj;
    if (function == null) {
      if (other.function != null)
        return false;
    } else if (!function.equals(other.function))
      return false;
    if (includeSpanScore != other.includeSpanScore)
      return false;
    return true;
  }