http://code.google.com/p/slim3/issues/detail?id=33 の反例

HasParentButIsIncomplete.java

import static org.junit.Assert.*;

import org.junit.Test;
import org.slim3.tester.AppEngineTestCase;

import com.google.appengine.api.datastore.Entity;

public class HasParentButIsIncomplete extends AppEngineTestCase {

    @Test
    public void counter_example() {
        Entity parent = new Entity("Hoge", "parent");
        Entity child = new Entity("Hoge", parent.getKey());

        Hoge model = HogeMeta.get().entityToModel(child);

        assertNotNull(model.key);
        assertNotNull(model.key.getParent());
        assertFalse(model.key.isComplete());
    }
}

Hoge.java

import org.slim3.datastore.Attribute;
import org.slim3.datastore.Model;

import com.google.appengine.api.datastore.Key;

@Model
public class Hoge {

    @Attribute(primaryKey = true)
    public Key key;

    public Key getKey() {
        return this.key;
    }

    public void setKey(Key key) {
        this.key = key;
    }
}