@BeforeEach
    final void createEnvs() throws IOException {
        final TestEnv testEnv1 = createEnv();
        lmdbEnv1 = testEnv1.lmdbEnv;
        dbDir1 = testEnv1.dbDir;

        final TestEnv testEnv2 = createEnv();
        lmdbEnv2 = testEnv2.lmdbEnv;
        dbDir2 = testEnv2.dbDir;
    }
Useful for comparing the behaviour of two different envs
stroom-lmdb/src/test/java/stroom/lmdb/AbstractDualEnvLmdbTest.java