two find() calls, same session: SQL selects = 1, same instance = true
after clear(): SQL selects = 2, same instance as before = false
SQL> select e1_0.id,e1_0.city,e1_0.zip,e1_0.department_id,e1_0.level,e1_0.name,e1_0.salary from Employee e1_0 where e1_0.id=?
SQL> select e1_0.id,e1_0.city,e1_0.zip,e1_0.department_id,e1_0.level,e1_0.name,e1_0.salary from Employee e1_0 where e1_0.id=?
a different session: SQL selects = 1 (the first-level cache is per session)
