How to persist several rows in a #OneToMany relationship with a composite key - jpa

Question

I have found this OLD link which resolve my database schema:
http://randomthoughtsonjavaprogramming.blogspot.com.es/2014/09/jpa-manytoone-with-composite-primary-key.html
I can retrieve data and everything works great, but I don't know how to insert data as I posted to the author.
In my case for every guild inserted I need to insert several guildranks at the same time, so one use case will be:
BEGIN TRANSACTION
GUILD
Guildname1
GUILDRANK
Guildname1, 1
Guildname1, 2
Guildname1, 3
Guildname1, 4
END TRANSACTION
Any suggestions?
Thanks
UPDATE
#Entity
#NamedQueries({
#NamedQuery(name = "Cuestionario.findAll", query = "SELECT c FROM Cuestionario c")
})
public class Cuestionario implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "ID", nullable = false)
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#OneToMany(mappedBy = "cuestionario", cascade = { CascadeType.PERSIST })
private Set<Hoja> hojas;
}
#Entity
#NamedQuery(name = "Hoja.findAll", query = "SELECT h FROM Hoja h")
public class Hoja implements Serializable {
private static final long serialVersionUID = 1L;
#EmbeddedId
private HojaPK id;
// bi-directional many-to-one association to Cuestionario
#ManyToOne(cascade = { CascadeType.PERSIST, CascadeType.REMOVE })
#JoinColumn(name = "ID", insertable = false, updatable = false)
private Cuestionario cuestionario;
public Hoja() {
}
}
#Embeddable
public class HojaPK implements Serializable {
// default serial version id, required for serializable classes.
private static final long serialVersionUID = 1L;
//Correspond with "id" in Cuestionario
#Column(name = "ID")
private long id;
private int dia;
public HojaPK() {
}
}
persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="pu"
transaction-type="RESOURCE_LOCAL">
<properties>
<property name="javax.persistence.jdbc.user" value="***" />
<property name="javax.persistence.jdbc.password" value="***" />
<property name="javax.persistence.jdbc.url"
value="jdbc:sqlserver://localhost:1433;databaseName=mydatabase" />
<property name="javax.persistence.jdbc.driver"
value="com.microsoft.sqlserver.jdbc.SQLServerDriver" />
<property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect" />
<property name="hibernate.show_sql" value="true" />
<!--
<property name="hibernate.hbm2ddl.auto" value="update" />
-->
<property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
<property name="hibernate.connection.charSet" value="UTF-8" />
</properties>
</persistence-unit>
</persistence>
TestCase.java
EntityManagerFactory emf = Persistence.createEntityManagerFactory("pu");
EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
em.persist(cuestionario);
em.flush();
for (int i = 0; i <= 32; i++) {
HojaPK hojaPk = new HojaPK(cuestionario.getId(), i);
Hoja hoja = new Hoja();
hoja.setId(hojaPk);
em.persist(hoja);
}
em.getTransaction().commit();
em.close();
emf.close();