private List<Source> readSourceAttribute(Element sectionElement) {
        List<Source> sources = new ArrayList<>();
        String sourceAttributeString = sectionElement.getAttribute("source");
        if (sourceAttributeString != null) {
            for (String sourceName : sourceAttributeString.split(" ")) {
                if (sourceName.isEmpty()) continue;
                if ("*".equals(sourceName))
                    sources.add(Source.any);
                else
                    sources.add(new Source(sourceName));
            }
        }
        return sources;
    }
Returns the page element corresponding to the given node, never null
container-search/src/main/java/com/yahoo/search/pagetemplates/config/PageTemplateXMLReader.java