In project https://github.com/chtiJBUG/onboarding-nautic-project
when running the TestBirthday reduction

TestBirthdayReduction : [Error: could not access/write property (seasonType) in: org.chtijbug.example.swimmingpool.Period] [Near :

the source code of the rule is
package org.training.leisure.swimmingpool;

import java.lang.Number;
import org.chtijbug.example.swimmingpool.CalculatedAttribute;
import org.chtijbug.example.swimmingpool.Price;
import org.chtijbug.example.swimmingpool.Person;
import org.chtijbug.example.swimmingpool.Period;
import org.chtijbug.example.swimmingpool.PriceType;

rule "BirthdayReduction"
dialect "mvel"
ruleflow-group "reduction"
when
ccat : CalculatedAttribute( key == "IsPersonBirthday" , stringValue == "true" )
pper : Person( calculatedAttributeList contains ccat , sprice : standardPrice > 0.0B )
not (pprice : Price( description == "BirthdayReduction" ) and Person( priceList contains pprice , this == pper ))
Period( seasonType == SeasonType.day )
then
Price nprice = new Price();
nprice.setDescription( "BirthdayReduction" );
nprice.setAmount( sprice.divide(new BigDecimal("10.0"),BigDecimal.ROUND_HALF_UP) );
nprice.setPriceType( PriceType.promotion );
insert( nprice );
pper.addPrice( nprice );
modify( pper )

end