can drools call methods
package droolsexample
// list any import classes here.
import com.sample.ItemCity;
import java.math.BigDecimal;
// declare any global variables here
dialect "java"
rule "Pune Medicine Item"
when
$item : ItemCity (purchaseCity == ItemCity.City.PUNE,
typeofItem == ItemCity.Type.MEDICINES)
then
BigDecimal tax = new BigDecimal(0.0);
$item.setLocalTax(tax.multiply($item.getSellPrice()));
end