How the driver knows that next sequence item is available/not while executing current sequence item

OVM
,
1

My requirement is that how the driver knows whether the next sequence item is available/not while executing the current sequence item.

Demonstrating with the example for easy understanding.

My sequence code looks like this :
class my_seq extends ovm_sequence();
task body();

start_item();

finish_item()

or

`ovm_do_on_with().

endtask

endclass

The driver code looks like this:

class driver extends ovm_driver();
task run_phase()

forever
begin
sequence_item_port.get_next_item(req)
drive_to_dut();
sequence_item_port.item_done()
end
endtask

task drive_to_dut;

// here i need to know whether next item is available in sequencer/not.
//if next item is not available
if.a = {req.a,0};
//if next item is available. i have to get next item and then
if.a = {req.a , req.b};req.a = current sequence item and req.b is next sequence item

endtask
endclass

Thanks,
-Murali