FNRET(addNode(cib, XML_CIB_TAG_CONSTRAINTS, xml_node));
FNRET(add_node_copy(cib, XML_CIB_TAG_CONSTRAINTS, xml_node));
addConstraint(xmlNodePtr cib, cibConstraint *xml_node){    if(findConstraint(cib, ID(xml_node)) != NULL) FNRET(-1);    FNRET(addNode(cib, XML_CIB_TAG_CONSTRAINTS, xml_node));}