@Test
void managerOf() {

    assertThrows(NullPointerException.class, () -> instance.managerOf(null));
    assertThrows(SpeedmentException.class, () -> instance.managerOf(Integer.class));
    final Manager<String> manager = new MockStringManager();
    instance.put(manager);
    assertDoesNotThrow(() -> instance.managerOf(manager.getEntityClass()));
}