code: public boolean isObjectModelSupported(String objectModel) {
  		
              if (objectModel == null) {
                  String fmsg = XSLMessages.createXPATHMessage(
                          XPATHErrorResources.ER_OBJECT_MODEL_NULL,
                          new Object[] { this.getClass().getName() } );
  
                  throw new NullPointerException( fmsg );
              }
  		
              if (objectModel.length() == 0) {
                  String fmsg = XSLMessages.createXPATHMessage(
                          XPATHErrorResources.ER_OBJECT_MODEL_EMPTY,
                          new Object[] { this.getClass().getName() } );
                  throw new IllegalArgumentException( fmsg );
              }
  		
  	    // know how to support default object model, W3C DOM
              if (objectModel.equals(XPathFactory.DEFAULT_OBJECT_MODEL_URI)) {
                  return true;
              }
  		
              // don't know how to support anything else
              return false;
  	}
docs: <p>Is specified object model supported by this
  <code>XPathFactory</code>?</p>
  
  @param objectModel Specifies the object model which the returned
  <code>XPathFactory</code> will understand.
  
  @return <code>true</code> if <code>XPathFactory</code> supports
  <code>objectModel</code>, else <code>false</code>.
  
  @throws NullPointerException If <code>objectModel</code> is <code>null</code>.
  @throws IllegalArgumentException If <code>objectModel.length() == 0</code>.