public StringBuilder getProcessingIdForOperators_() {
   if (operators_ == null || operators_.isEmpty()) return null;
   StringBuilder result = new StringBuilder("OPER");
   for (OpAttribute opAttribute : OpAttribute.values()) {
     if (operators_.containsKey(opAttribute.name()))
       result
           .append("@")
           .append(opAttribute.name())
           .append("=")
           .append(operators_.get(opAttribute.name()));
   }
   return result;
 }
 public void setNullOp_(final AnHourBeforeResult.OpAttribute... attributes) {
   if (attributes == null) throw new IllegalArgumentException();
   for (OpAttribute attribute : attributes) operators_.put(attribute.name(), "is null");
 }
 public void clearOp_(final AnHourBeforeResult.OpAttribute... attributes) {
   if (attributes == null) throw new IllegalArgumentException();
   for (OpAttribute attribute : attributes) operators_.remove(attribute.name());
 }