@Test
public void upper_level() {

	// given
	String levelName = "animal";
	// when
	Level level = transform(codemap, levelName);
	log.info("produced level '{}':\n{}", levelName, level.formatted());
	// then
	Component domestic = new Component("domestic");
	Component rodent = new Component("rodent");
	assertThat(level.name).isEqualTo(levelName);
	assertThat(level.components).containsExactly(domestic, rodent);
	assertThat(level.dependencies).containsExactly(
			new ComponentDep(domestic, rodent)
	);
	assertThat(level.dependency(domestic, rodent).strength).isEqualTo(2);
	assertThat(level.component("domestic").size).isGreaterThan(level.component("rodent").size);
}