public function appendTab($str=null, $tabNum=1) {

        $tab = "";
        for ( $i = 0; $i < $tabNum; $i++ ) {
            $tab .= "\t";
        }
        $this->appendLine($tab.$str);

    }
public function appendTab($str=null, $tabNum=1) {

        $tab = "";
        for ( $i = 0; $i < $tabNum; $i++ ) {
            $tab .= "\t";
        }
        $this->appendLine($tab.$str);

    }
public function appendTab ( $ str = null , $ tabNum = 1 ) { $ tab = "" ; for ( $ i = 0 ; $ i < $ tabNum ; $ i ++ ) { $ tab .= "\t" ; } $ this -> appendLine ( $ tab . $ str ) ; }
append line with tab symbol
append line with tab symbol