How to retrieve qualifier information from TRowResult in Thrift(v0.80) Hbase(v0.90) Php

[Zebra Zhao]

Hi All,

I created a Hbase table with following schema:

<row_id>  -->  {<cf_id>: [<qualifier_id1>,<qualifier_id2>,...]}

Row record sample:

<"00001"> {<"cf_01">:<"qualifier_01">,<"qualifier_02">,...]}

I wrote following code to retrieve the all the qualifier name associated
with one TRowResult. Here is the code:

$rowKey = "00001";
$rowResults = $client->getRow($tableName,$rowKey);

foreach ($rowResults as $rowresult){
if ($rowresult->row){
     echo( "row: {$rowresult->row}, cols: \n" );
     $values = $rowresult->columns;
     asort( $values );

     foreach ( $values as $k=>$v ) {
        echo( "  {$k} => {$v->value}\n" );
     }//foreach
   }//if
 }//foreach

However, the output didnot show any qualifier name:
row: 00001, cols:
cf_01 =>

My question is how to retrieve the qualifier information from a TRowResult.
Specifically, how to get "qualifier_01","qualifier_02" using above code.
I've looked up the Hbase.php  Hbase_type.php, but did not find the useful
information.
Any suggestion will be appreciated.

Thank you,
Zhao