[boost] Boost_Test: Initialize fixture only once

Hello All, I have a question about boost test. Please help. I have set of test_suites. Every test_suite consists of a bunch of test_cases. Every test case should be initialized before execution. So, I created Fixture for every test_suite. The problem is Fixture initialization takes a lot of time and boost creates it for every test_case (not for every test_suite) How to solve this? Best regards. Dima