code: DOMImplementationLS buildDOM3LoadAndSaveFactory() {
          DOMImplementationLS factory = null;
          try {
              DOMImplementationRegistry domRegistry = DOMImplementationRegistry.newInstance();
              factory = (DOMImplementationLS) domRegistry.getDOMImplementation("LS 3.0");
          } catch (Exception e) {
              LOGR.log(Level.WARNING, "Failed to create DOMImplementationLS", e);
          }
          return factory;
      }
docs: Builds a DOMImplementationLS factory that supports the
  "DOM Level 3 Load and Save" specification. It provides various factory
  methods for creating the objects required for loading and saving DOM
  nodes.
  
  @return A factory object, or <code>null</code> if one cannot be created
  (in which case a warning will be logged).
  
  @see <a href="https://www.w3.org/TR/DOM-Level-3-LS/">Document Object
  Model (DOM) Level 3 Load and Save Specification, Version 1.0</a>