code: public String getOutputProperty(String name) throws IllegalArgumentException
    {
  
      String value = null;
      OutputProperties props = m_outputFormat;
  
      value = props.getProperty(name);
  
      if (null == value)
      {
        if (!OutputProperties.isLegalPropertyKey(name))
          throw new IllegalArgumentException(XSLMessages.createMessage(XSLTErrorResources.ER_OUTPUT_PROPERTY_NOT_RECOGNIZED, new Object[]{name})); //"output property not recognized: "
                                            // + name);
      }
  
      return value;
    }
docs: Get an output property that is in effect for the
  transformation.  The property specified may be a property
  that was set with setOutputProperty, or it may be a
  property specified in the stylesheet.
  
  @param name A non-null String that specifies an output
  property name, which may be namespace qualified.
  
  @return The string value of the output property, or null
  if no property was found.
  
  @throws IllegalArgumentException If the property is not supported.
  
  @see javax.xml.transform.OutputKeys