javadocs updated

redisson/src/main/java/org/redisson/api/RMap.java

@@ -102,7 +102,7 @@ public interface RMap<K, V> extends ConcurrentMap<K, V>, RExpirable, RMapAsync<K
      *
      * @param key - map key
      * @param value - map value
-     * @return <code>null</code> if key is doesn't exists in the hash and value hasn't been set.
+     * @return <code>null</code> if key doesn't exist in the hash and value hasn't been set.
      *         Previous value if key already exists in the hash and new value has been stored.
      */
     V putIfExists(K key, V value);

redisson/src/main/java/org/redisson/api/RMapReactive.java

@@ -342,7 +342,7 @@ public interface RMapReactive<K, V> extends RExpirableReactive {
      *
      * @param key - map key
      * @param value - map value
-     * @return <code>null</code> if key is doesn't exists in the hash and value hasn't been set.
+     * @return <code>null</code> if key doesn't exist in the hash and value hasn't been set.
      *         Previous value if key already exists in the hash and new value has been stored.
      */
     Mono<V> putIfExists(K key, V value);

redisson/src/main/java/org/redisson/api/RMapRx.java

@@ -345,7 +345,7 @@ public interface RMapRx<K, V> extends RExpirableRx {
      *
      * @param key - map key
      * @param value - map value
-     * @return <code>null</code> if key is doesn't exists in the hash and value hasn't been set.
+     * @return <code>null</code> if key doesn't exist in the hash and value hasn't been set.
      *         Previous value if key already exists in the hash and new value has been stored.
      */
     Maybe<V> putIfExists(K key, V value);