Remove old method

core-java-modules/core-java-streams-2/src/test/java/com/baeldung/streams/StreamAddUnitTest.java

@@ -53,10 +53,4 @@ public class StreamAddUnitTest {
           Stream.of(elem)),
           StreamSupport.stream(spliterator, /* parallel= */ false));
     }
-    
-    private <T> Stream<T> insertInStream(Stream<T> stream, T elem, int index) {
-        List<T> result = stream.collect(Collectors.toList());
-        result.add(index, elem);
-        return result.stream();
-    }
 }