diff --git a/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java b/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
index 36a946cc9..fccc23d83 100644
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
@@ -54,17 +54,16 @@ public abstract class AbstractDocument implements Document {
 
   @Override
   public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) {
-    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(el -> el != null)
+    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(Objects::nonNull)
         .map(el -> (List<Map<String, Object>>) el).findAny();
-    return any.isPresent() ? any.get().stream().map(constructor) : Stream.empty();
+    return any.map(maps -> maps.stream().map(constructor)).orElseGet(Stream::empty);
   }
 
   @Override
   public String toString() {
     StringBuilder builder = new StringBuilder();
     builder.append(getClass().getName()).append("[");
-    properties.entrySet()
-        .forEach(e -> builder.append("[").append(e.getKey()).append(" : ").append(e.getValue()).append("]"));
+    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value).append("]"));
     builder.append("]");
     return builder.toString();
   }