public NutchDocument filter(NutchDocument doc,String url,WebPage page) throws IndexingException {
  for (  IndexingFilter indexingFilter : indexingFilters) {
    doc=indexingFilter.filter(doc,url,page);
    if (doc == null)     return null;
  }
  return doc;
}

public NutchDocument filter ( NutchDocument doc , String url , WebPage page ) throws IndexingException { for ( IndexingFilter indexingFilter : indexingFilters ) { doc = indexingFilter . filter ( doc , url , page ) ; if ( doc == null ) return null ; } return doc ; }
run all defined filters .
