In reply to uvm_user235:
The question is what is your objectice. I believe your code is useless, because all sequences are parameterized with the item. That mena it should generate seq_items.
But a sequence does not have to generate sequence items.
A virtual sequence is startring several other sequences, and it does not need a sequencer.
And any sequence can contain other sequences which are intended to run on the same sequencer.
Both cases are very useful,