code: public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
    {
  
      return operate(m_right.execute(xctxt));
    }
docs: Execute the operand and apply the unary operation to the result.
  
  
  @param xctxt The runtime execution context.
  
  @return An XObject that represents the result of applying the unary
  operation to the evaluated operand.
  
  @throws javax.xml.transform.TransformerException