KieBase kbase = new KieHelper().addContent(rule, ResourceType.DRL).build();
KieSession ksession = kbase.newKieSession();
FactType nodeType = kbase.getFactType( "org.drools.compiler", "Node" );
Object parent = nodeType.newInstance();
nodeType.set( parent, "value", "parent" );
ksession.insert( parent );
Object child = nodeType.newInstance();
nodeType.set( child, "value", "child" );