env.setVariable("TEST_VAR", "my test var value");
BOOST_REQUIRE_EQUAL(env.getValue("TEST_VAR"), std::string("my test var value"));
env.setVariable("TEST_VAR", "my new test var value", false /* no overwritting */);
BOOST_REQUIRE_EQUAL(env.getValue("TEST_VAR"), std::string("my test var value"));
env.unsetVariable("TEST_VAR");
BOOST_REQUIRE_EQUAL(env.getValue("TEST_VAR"), std::string(""));
env.setVariable("TEST_VAR", "my test var value");
BOOST_REQUIRE_EQUAL(env.getValue("TEST_VAR"), std::string("my test var value"));
env.setVariable("TEST_VAR", "my new test var value", false /* no overwritting */);
BOOST_REQUIRE_EQUAL(env.getValue("TEST_VAR"), std::string("my test var value"));
env.unsetVariable("TEST_VAR");
BOOST_REQUIRE_EQUAL(env.getValue("TEST_VAR"), std::string(""));