Enhance a slide in Lecture 08 deck

Author: 100yo

08-lambdas-and-stream-api/lecture/slides.md

@@ -930,15 +930,17 @@ double result = employees.reduce(
 <br>
 
 ```java
+// Java 8+ (returns modifiable List)
 List<Integer> list = Stream.of(1, 2, 3, 4, 5)
                            .collect(Collectors.toList()); // [1, 2, 3, 4, 5]
 
-// since Java 16
+// Java 16+ (returns unmodifiable List)
 List<Integer> list = Stream.of(1, 2, 3, 4, 5)
                            .toList();
-
 ```
 
+- По контракт `Stream.toList()` е еквивалентен на `Collectors.toUnmodifiableList()`.
+
 ---
 
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