testdata for IDEA-123848

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/IDEA123848.java

@@ -0,0 +1,27 @@
+import java.util.*;
+
+import static java.util.stream.Collectors.groupingBy;
+import static java.util.stream.Collectors.mapping;
+import static java.util.stream.Collectors.toList;
+
+class Test {
+
+  private static void run() {
+    List<R> list = Arrays.asList(new R());
+
+    System.out.println(
+      list.stream()
+        .collect(groupingBy(r -> r.get(String.class), mapping(r -> r.get(String.class),toList())
+        ))
+    );
+  }
+
+  static class R {
+    <T> T get(Class<T> clazz) {
+      if (clazz == String.class)
+        return (T) "string";
+
+      throw new IllegalArgumentException();
+    }
+  }
+}