@Override
 public int hashCode() {
   final int prime = 31;
   int result = super.hashCode();
   result = prime * result + ((function == null) ? 0 : function.hashCode());
   result = prime * result + (includeSpanScore ? 1231 : 1237);
   return result;
 }
 @Override
 public boolean equals(Object obj) {
   if (this == obj) return true;
   if (!super.equals(obj)) return false;
   if (getClass() != obj.getClass()) return false;
   PayloadBoostTermQuery other = (PayloadBoostTermQuery) 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;
 }