@Test
public void testEqualsObject() {

    final LeftTupleSource ts = new MockTupleSource( 1 );
    final ObjectSource os = new MockObjectSource( 2 );
    InternalKnowledgeBase kBase = (InternalKnowledgeBase) KnowledgeBaseFactory.newKnowledgeBase();
    BuildContext buildContext = new BuildContext( kBase );
    
    final BetaNode j1 = new JoinNode( 1,
                                      ts,
                                      os,
                                      EmptyBetaConstraints.getInstance(),
                                      buildContext );
    final BetaNode j2 = new JoinNode( 2,
                                      ts,
                                      os,
                                      EmptyBetaConstraints.getInstance(),
                                      buildContext );
    final BetaNode n1 = new NotNode( 3,
                                     ts,
                                     os,
                                     EmptyBetaConstraints.getInstance(),
                                     buildContext );
    final BetaNode n2 = new NotNode( 4,
                                     ts,
                                     os,
                                     EmptyBetaConstraints.getInstance(),
                                     buildContext );
    assertEquals( j1,
                  j1 );
    assertEquals( j2,
                  j2 );
    assertEquals( j1,
                  j2 );
    assertEquals( n1,
                  n1 );
    assertEquals( n2,
                  n2 );
    assertEquals( n1,
                  n2 );
    assertFalse( j1.equals( n1 ) );
    assertFalse( j1.equals( n2 ) );
    assertFalse( n1.equals( j1 ) );
    assertFalse( n1.equals( j2 ) );
}