Set<XmlTag> (@NotNull MavenDomProjectModel projectDom, @NotNull final Project project) { final Set<XmlTag> properties = new HashSet<>(); Processor<MavenDomProperties> collectProcessor = mavenDomProperties -> { XmlTag propertiesTag = mavenDomProperties.getXmlTag(); if (propertiesTag != null) { ContainerUtil.addAll(properties, propertiesTag.getSubTags()); } return false; }; processProperties(projectDom, collectProcessor, project); return properties; }