Parsed test spec with 2 sessions

starting permutation: ins com upd
step ins:  INSERT INTO bar VALUES (42); 
step com:  COMMIT; 
step upd:  UPDATE foo SET b = 'Hello World'; 

starting permutation: ins upd com
step ins:  INSERT INTO bar VALUES (42); 
step upd:  UPDATE foo SET b = 'Hello World';  <waiting ...>
step com:  COMMIT; 
step upd: <... completed>

starting permutation: upd ins com
step upd:  UPDATE foo SET b = 'Hello World'; 
step ins:  INSERT INTO bar VALUES (42); 
step com:  COMMIT; 
