title: org.hibernate.MappingException: Could not determine type for: java.util.List, at table: Schedule_assignedRoles, for columns: assignedRoles
body: <p>I need a help, I'm trying to use a Map, but I got this error:</p>
  
  <blockquote>
    <p>Caused by: org.hibernate.MappingException: Could not determine type for: java.util.List, at table: Schedule_assignedRoles, for columns: [org.hibernate.mapping.Column(assignedRoles)]
        at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:390)
        at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:363)
        at org.hibernate.mapping.Collection.validate(Collection.java:310)
        at org.hibernate.mapping.IndexedCollection.validate(IndexedCollection.java:74)
        at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:333)
        at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:443)
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:802)</p>
  </blockquote>
  
  <p>here my code:</p>
  
  <pre><code>@Entity
  public class Schedule extends PersistentObject implements Comparable&lt;Schedule&gt; {
     private String title;
  
     @ManyToOne
     private Agent target;
  
     @ElementCollection
     @MapKeyColumn(nullable = false)
     @Column(nullable = false)
     private Map&lt;Long, List&lt;Role&gt;&gt; assignedRoles = new HashMap&lt;&gt;();
  
     //gets e setters
  }
  </code></pre>
  
  <p>thank's! :D</p>