@Test
void removeEldestEntry() {

    LRUMap<String, String> map = new LRUMap<>(3);
    map.put("1", "1");
    map.put("2", "2");
    map.put("3", "3");
    assertEquals(3, map.size());
    map.put("4", "4");
    assertEquals(3, map.size());
    assertFalse(map.containsKey("1"));
    assertTrue(map.containsKey("2"));
    assertTrue(map.containsKey("4"));
    map.put("5", "5");
    assertEquals(3, map.size());
    assertFalse(map.containsKey("2"));
    assertTrue(map.containsKey("4"));
    assertTrue(map.containsKey("5"));
}