code: public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
    {
      return m_arg0.execute(xctxt).xstr().startsWith(m_arg1.execute(xctxt).xstr())
             ? XBoolean.S_TRUE : XBoolean.S_FALSE;
    }
docs: Execute the function.  The function must return
  a valid object.
  @param xctxt The current execution context.
  @return A valid XObject.
  
  @throws javax.xml.transform.TransformerException