/**
* Tests adding Connections.
*/
public void testAddRemoveConnection() {
Connection conn = new SimpleConnection() {
public boolean contains(double mx, double my) { return true; }
};
diagram.addChild(conn);
assertEquals(diagram, conn.getParent());
assertEquals(conn, diagram.getChildAt(6.0, 5.0));
diagram.removeChild(conn);
assertEquals(NullElement.getInstance(), diagram.getChildAt(6.0, 5.0));
}