IDEA-120784 "Class is public should be declared in a file named <Classname>.java" for inner interface

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newMethodRef/AfterCollectors1.java

@@ -8,7 +8,7 @@ interface Function<T, R> {
    R apply(T t);
 }
 
-public final class Collectors {
+final class Collectors {
     public static <T>
     Collector<List<T>> toList() {
         return null;