void (@NotNull ElementStub stub, @NotNull IndexSink sink) { final String namespaceKey = stub.getNamespaceKey(); if (StringUtil.isNotEmpty(namespaceKey)) { sink.occurrence(DomNamespaceKeyIndex.KEY, namespaceKey); } final String elementClass = stub.getElementClass(); if (elementClass != null) { sink.occurrence(DomElementClassIndex.KEY, elementClass); } }