code: public static String getBeginActionURI( String requestURI )
      {
          // Translate this to a request for the begin action ("begin.do") for this PageFlowController.
          InternalStringBuilder retVal = new InternalStringBuilder();
          int lastSlash = requestURI.lastIndexOf( '/' );
  
          if ( lastSlash != -1 )
          {
              retVal.append( requestURI.substring( 0, lastSlash ) );
          }
  
          retVal.append( '/' ).append( BEGIN_ACTION_NAME ).append( ACTION_EXTENSION );
          return retVal.toString();
      }
docs: Get a URI for the "begin" action in the PageFlowController associated with the given
  request URI.
  
  @return a String that is the URI for the "begin" action in the PageFlowController associated
  with the given request URI.