Object readResolve() {
   if (amountTypeString != null) {
     amountType = AmountType.valueOf(amountTypeString);
   }
   if (buildCountTypeString != null) {
     buildCountType = BuildCountType.valueOf(buildCountTypeString);
   }
   return super.readResolve();
 }
 @DataBoundConstructor
 public AbstractBuildTrendFilter(
     String buildCountTypeString,
     float amount,
     String amountTypeString,
     String includeExcludeTypeString) {
   super(includeExcludeTypeString);
   this.buildCountTypeString = buildCountTypeString;
   this.buildCountType = BuildCountType.valueOf(buildCountTypeString);
   this.amount = amount;
   this.amountTypeString = amountTypeString;
   this.amountType = AmountType.valueOf(amountTypeString);
 }