use property readPast on a query run class

I have a question about pessimosticklocks

we know how to it on below context 

MyTestTable myTestTable;

i thought a queryrun could do the same like select code in x++ until I run in this scenario:

    myTestTable.readPast(true);

    ttsbegin;

    selectpessimisticLockfirstOnly myTestTable where myTestTable.Processed == NoYes::No;

      if (myTestTable)

now we do the same on query run

    query.addDataSource(tableNum(MyTestTable));

    query.dataSourceNo(1).addRange(fieldnum(MyTestTable, Processed)).value(SysQuery::value(NoYes::No));

    query.dataSourceNo(1).concurrencyModel(ConcurrencyModel::Pessimistic);

    query.dataSourceNo(1).firstOnly(true);

where can I set my readPast(true).... 

I can't find it :-(