How to check the source of analysis task in Oracle Performance Analyzer?

We have provided sql tuning set as input to the analysis task of performance analyzer

variable l_task_id VARCHAR2(64);

exec :l_task_id:=dbms_sqlpa.create_analysis_task(
     sqlset_name => ''
    , sqlset_owner=>''
    ,task_name => '');

Now i want to list all the tasks associated with the sql tuning set. I have tried below ways but they are not working

select parameter_name,parameter_value 
from dba_advisor_exec_parameters 
where task_name='' and parameter_name='SQLSET_NAME';

But the result is showing "NOT USED" for column parameter_value |parameter_name | parameter_value| |-------------------- | ------------------| |SQLSET_NAME UNUSED||