CaseInsensitiveConcurrentHashMap { public V put(final String key, final V value) { return this.map.put(key.toLowerCase(), value); }  V put(final String key, final V value); V get(final String key); boolean containsKey(final String key); V remove(final String key); List<String> getKeys();  }
@Test public void testPut() { this.map.put(LOWER_KEY, VALUE_1); assertThat(this.map.containsKey(LOWER_KEY)).isTrue(); assertThat(this.map.containsKey(UPPER_KEY)).isTrue(); assertThat(this.map.containsKey(WRONG_KEY)).isFalse(); }