code: protected void serializePI(ProcessingInstruction node)
          throws SAXException {
          ProcessingInstruction pi = node;
          String name = pi.getNodeName();
  
          // well-formed=true
          if ((fFeatures & WELLFORMED) != 0) {
              isPIWellFormed(node);
          }
  
          // apply the LSSerializer filter
          if (!applyFilter(node, NodeFilter.SHOW_PROCESSING_INSTRUCTION)) {
              return;
          }
  
          // String data = pi.getData();
          if (name.equals("xslt-next-is-raw")) {
              fNextIsRaw = true;
          } else {
              this.fSerializer.processingInstruction(name, pi.getData());
          }
      }
docs: Serializes an ProcessingInstruction Node.
  
  @param node The ProcessingInstruction Node to serialize