Working one to many JDBI mapping

ContactPhonesTest.kt

import org.junit.jupiter.api.Test
import tj.alif.core.app.db.RepositoryTest
import org.jdbi.v3.core.result.RowView
import java.lang.Integer


data class Contact (
        val id: Int,
        val name: String,
        var phones: MutableList<Phone> = mutableListOf()
) {
    fun addPhone(phone: Phone) = phones.add(phone)
}

data class Phone (val phone_id: Integer,
             val type: String,
             val number: String
)


class ContactPhonesTest: RepositoryTest() {

    @Test
    fun `some test`() {
        val SELECT_ALL = ("select contacts.id, name, "
                + "phones.id phone_id, type, phones.number "
                + "from contacts left join phones on contacts.id = phones.contact_id")

        val contacts = db.createQuery(SELECT_ALL)
//                .registerRowMapper(BeanMapper.factory(Contact::class.java, "c"))
//                .registerRowMapper(BeanMapper.factory(Phone::class.java, "p"))
                .reduceRows(linkedMapOf()) { map: LinkedHashMap<Int, Contact>, rowView: RowView ->
                    val contact = map.computeIfAbsent(rowView.getColumn("id", Integer::class.java) as Int) {
                        rowView.getRow(Contact::class.java)
                    }

                    if (rowView.getColumn("phone_id", Integer::class.java) != null) {
                        contact.addPhone(rowView.getRow(Phone::class.java))
                    }
                    map
                }
                .toList()

        println(contacts)
    }
}