calling LSSerializer.writeToString on DOM Text node with white space causes NPE

FULL PRODUCT VERSION :
java version "1.5.0_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_01-b08)
Java HotSpot(TM) Client VM (build 1.5.0_01-b08, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
Calling LSSerializer.writeToString on a DOM Text node which contains only white space causes a org.w3c.dom.ls.LSException: java.lang.NullPointerException in at com.sun.org.apache.xml.internal.serialize.DOMSerializerImpl.writeToString(Unknown Source) which I think is a bug as the serializer should be able to deal with all types of DOM nodes.



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile and run the following test case:

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.Text;

import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSSerializer;

public class Test2005032102 {
  public static void main (String[] args) {
    try {
      DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
      documentBuilderFactory.setNamespaceAware(true);
      DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
      
      Document xmlDocument = documentBuilder.newDocument();
      
      String whitespace = "\r\n ";
      Text textNode = xmlDocument.createTextNode(whitespace);
      
      System.out.println("original text is:\r\n\"" + whitespace + "\"");
      
      String outerXML = getOuterXML(textNode);
      System.out.println("OuterXML is:\r\n\"" + outerXML + "\"");
      
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
  
  public static String getOuterXML (Node node) {
    DOMImplementationLS domImplementation = (DOMImplementationLS) node.getOwnerDocument().getImplementation();
    LSSerializer lsSerializer = domImplementation.createLSSerializer();
    if (!(node instanceof Document)) {
      lsSerializer.getDomConfig().setParameter("xml-declaration", false);
    }
    return lsSerializer.writeToString(node);
  }

}

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The program should run without throwing an exception, it should output the serialization of the Text node where the serialization of a Text node is its text content, in this case the white space.
ACTUAL -
output on the console is:

original text is:
"
    "
org.w3c.dom.ls.LSException: java.lang.NullPointerException
        at com.sun.org.apache.xml.internal.serialize.DOMSerializerImpl.writeToString(Unknown Source)
        at Test2005032102.getOuterXML(Test2005032102.java:40)
        at Test2005032102.main(Test2005032102.java:25)


ERROR MESSAGES/STACK TRACES THAT OCCUR :
org.w3c.dom.ls.LSException: java.lang.NullPointerException
        at com.sun.org.apache.xml.internal.serialize.DOMSerializerImpl.writeToString(Unknown Source)
        at Test2005032102.getOuterXML(Test2005032102.java:40)
        at Test2005032102.main(Test2005032102.java:25)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.Text;

import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSSerializer;

public class Test2005032102 {
  public static void main (String[] args) {
    try {
      DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
      documentBuilderFactory.setNamespaceAware(true);
      DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
      
      Document xmlDocument = documentBuilder.newDocument();
      
      String whitespace = "\r\n ";
      Text textNode = xmlDocument.createTextNode(whitespace);
      
      System.out.println("original text is:\r\n\"" + whitespace + "\"");
      
      String outerXML = getOuterXML(textNode);
      System.out.println("OuterXML is:\r\n\"" + outerXML + "\"");
      
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
  
  public static String getOuterXML (Node node) {
    DOMImplementationLS domImplementation = (DOMImplementationLS) node.getOwnerDocument().getImplementation();
    LSSerializer lsSerializer = domImplementation.createLSSerializer();
    if (!(node instanceof Document)) {
      lsSerializer.getDomConfig().setParameter("xml-declaration", false);
    }
    return lsSerializer.writeToString(node);
  }

}
---------- END SOURCE ----------