code: public int getAnalysisBits()
    {
    	org.apache.xalan.templates.ElemVariable vvar = getElemVariable();
    	if(null != vvar)
    	{
    		XPath xpath = vvar.getSelect();
    		if(null != xpath)
    		{
  	  		Expression expr = xpath.getExpression();
  	  		if(null != expr && expr instanceof PathComponent)
  	  		{
  	  			return ((PathComponent)expr).getAnalysisBits();
  	  		}
    		}
    	}
      return WalkerFactory.BIT_FILTER;
    }
docs: Get the analysis bits for this walker, as defined in the WalkerFactory.
  @return One of WalkerFactory#BIT_DESCENDANT, etc.