### Question:
MapUtils extends org.apache.commons.collections.MapUtils { public static Map<String, ?> putPath( String path, Object value ) { return putPath( null, path, value ); }  static void addMapSet( Map<A, Set<B>> map, A a, B b ); @SuppressWarnings("unchecked") static void addMapSet( Map<A, Set<B>> map, boolean ignoreCase, A a, B b ); static void addMapMapSet( Map<A, Map<B, Set<C>>> map, A a, B b, C c ); @SuppressWarnings("unchecked") static void addMapMapSet( Map<A, Map<B, Set<C>>> map, boolean ignoreCase, A a, B b, C c ); @SuppressWarnings("unchecked") static void addMapMapMapSet( Map<A, Map<B, Map<C, Set<D>>>> map, boolean ignoreCase, A a, B b,
                                                     C c, D d ); static C getMapMap( Map<A, Map<B, C>> map, A a, B b ); static void addMapList( Map<A, List<B>> map, A a, B b ); static void addListToMapList( Map<A, List<B>> map, A a, List<B> b ); @SuppressWarnings("unchecked") static V getValue( Map<K, ?> map, K k ); @SuppressWarnings("unchecked") static Map<?, ?> map( Object... objects ); static Map.Entry<K, V> entry( K k, V v ); static K getFirstKey( Map<K, V> map ); static Map<String, V> filter( Map<String, V> map, String prefix, boolean removePrefix ); static Map<String, V> filter( Map<String, V> map, String prefix ); static Properties filter( Properties properties, String prefix, boolean removePrefix ); static Properties filter( Properties properties, String prefix ); @SuppressWarnings("unchecked") static Map<String, String> asMap( Properties properties ); static Map<String, Object> toStringObjectMap(Map<S, T> map); static HashMapBuilder<S, T> hashMap( S key, T value ); @SuppressWarnings("unchecked") static Map<String, List<?>> toMapList( Map<String, ?> m ); static Map<String, ?> putPath( String path, Object value ); @SuppressWarnings("unchecked") static Map<String, ?> putPath( Map<String, ?> map, String path, Object value ); static Map<K, V> emptyMapWithKeys( Map<K, V> map ); static boolean hasKeys( Map<?, ?> map, String... keys ); static boolean hasKeys( Map<?, ?> map, Set<String> keys );  }### Answer:
@Test public void testMapUtils() { Map<String, ?> map = MapUtils.putPath( "a.b.c", 5 ); logger.info( JsonUtils.mapToFormattedJsonString( map ) ); map = MapUtils.putPath( map, "a.c", 6 ); logger.info( JsonUtils.mapToFormattedJsonString( map ) ); }