Requirements=nnbd-strong flag added to the 'late' tests
diff --git a/LanguageFeatures/nnbd/late_A01_t01.dart b/LanguageFeatures/nnbd/late_A01_t01.dart
index c53b0ab..f278930 100644
--- a/LanguageFeatures/nnbd/late_A01_t01.dart
+++ b/LanguageFeatures/nnbd/late_A01_t01.dart
@@ -16,6 +16,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A01_t02.dart b/LanguageFeatures/nnbd/late_A01_t02.dart
index ca93446..f3eab0e 100644
--- a/LanguageFeatures/nnbd/late_A01_t02.dart
+++ b/LanguageFeatures/nnbd/late_A01_t02.dart
@@ -16,6 +16,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A02_t01.dart b/LanguageFeatures/nnbd/late_A02_t01.dart
index f2e18c2..d5d25c5 100644
--- a/LanguageFeatures/nnbd/late_A02_t01.dart
+++ b/LanguageFeatures/nnbd/late_A02_t01.dart
@@ -18,6 +18,7 @@
  * @issue 39801
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A02_t02.dart b/LanguageFeatures/nnbd/late_A02_t02.dart
index 9afad67..2535753 100644
--- a/LanguageFeatures/nnbd/late_A02_t02.dart
+++ b/LanguageFeatures/nnbd/late_A02_t02.dart
@@ -18,6 +18,7 @@
  * @issue 39801
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A03_t01.dart b/LanguageFeatures/nnbd/late_A03_t01.dart
index 3a8bbaa..8b0c9f2 100644
--- a/LanguageFeatures/nnbd/late_A03_t01.dart
+++ b/LanguageFeatures/nnbd/late_A03_t01.dart
@@ -22,6 +22,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A03_t02.dart b/LanguageFeatures/nnbd/late_A03_t02.dart
index 5772442..50eab0a 100644
--- a/LanguageFeatures/nnbd/late_A03_t02.dart
+++ b/LanguageFeatures/nnbd/late_A03_t02.dart
@@ -22,6 +22,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A03_t03.dart b/LanguageFeatures/nnbd/late_A03_t03.dart
index 543b868..96cd1c1 100644
--- a/LanguageFeatures/nnbd/late_A03_t03.dart
+++ b/LanguageFeatures/nnbd/late_A03_t03.dart
@@ -20,6 +20,7 @@
  * @issue 39802
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A03_t04.dart b/LanguageFeatures/nnbd/late_A03_t04.dart
index fa1283b..537433f 100644
--- a/LanguageFeatures/nnbd/late_A03_t04.dart
+++ b/LanguageFeatures/nnbd/late_A03_t04.dart
@@ -19,6 +19,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A04_t01.dart b/LanguageFeatures/nnbd/late_A04_t01.dart
index bfe619a..72336a6 100644
--- a/LanguageFeatures/nnbd/late_A04_t01.dart
+++ b/LanguageFeatures/nnbd/late_A04_t01.dart
@@ -21,6 +21,7 @@
  * @issue 38734
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A04_t02.dart b/LanguageFeatures/nnbd/late_A04_t02.dart
index c0a991a..487d6ec 100644
--- a/LanguageFeatures/nnbd/late_A04_t02.dart
+++ b/LanguageFeatures/nnbd/late_A04_t02.dart
@@ -21,6 +21,7 @@
  * @issue 38734
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A04_t03.dart b/LanguageFeatures/nnbd/late_A04_t03.dart
index 32ef503..be22798 100644
--- a/LanguageFeatures/nnbd/late_A04_t03.dart
+++ b/LanguageFeatures/nnbd/late_A04_t03.dart
@@ -21,6 +21,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A04_t04.dart b/LanguageFeatures/nnbd/late_A04_t04.dart
index fbd6c7e..ae1dcbe 100644
--- a/LanguageFeatures/nnbd/late_A04_t04.dart
+++ b/LanguageFeatures/nnbd/late_A04_t04.dart
@@ -21,6 +21,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A05_t01.dart b/LanguageFeatures/nnbd/late_A05_t01.dart
index 4501d14..4f85786 100644
--- a/LanguageFeatures/nnbd/late_A05_t01.dart
+++ b/LanguageFeatures/nnbd/late_A05_t01.dart
@@ -20,6 +20,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A05_t02.dart b/LanguageFeatures/nnbd/late_A05_t02.dart
index f3b5abd..eb129cc 100644
--- a/LanguageFeatures/nnbd/late_A05_t02.dart
+++ b/LanguageFeatures/nnbd/late_A05_t02.dart
@@ -20,6 +20,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A05_t03.dart b/LanguageFeatures/nnbd/late_A05_t03.dart
index 1035149..0d5dc78 100644
--- a/LanguageFeatures/nnbd/late_A05_t03.dart
+++ b/LanguageFeatures/nnbd/late_A05_t03.dart
@@ -19,6 +19,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A05_t04.dart b/LanguageFeatures/nnbd/late_A05_t04.dart
index d20140f..8fd7c08 100644
--- a/LanguageFeatures/nnbd/late_A05_t04.dart
+++ b/LanguageFeatures/nnbd/late_A05_t04.dart
@@ -19,6 +19,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A06_t01.dart b/LanguageFeatures/nnbd/late_A06_t01.dart
index 4e442f1..dd97d9a 100644
--- a/LanguageFeatures/nnbd/late_A06_t01.dart
+++ b/LanguageFeatures/nnbd/late_A06_t01.dart
@@ -15,6 +15,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A06_t02.dart b/LanguageFeatures/nnbd/late_A06_t02.dart
index 637b4da..af92def 100644
--- a/LanguageFeatures/nnbd/late_A06_t02.dart
+++ b/LanguageFeatures/nnbd/late_A06_t02.dart
@@ -15,6 +15,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A06_t03.dart b/LanguageFeatures/nnbd/late_A06_t03.dart
index 2ab8f87..e2d02bd 100644
--- a/LanguageFeatures/nnbd/late_A06_t03.dart
+++ b/LanguageFeatures/nnbd/late_A06_t03.dart
@@ -15,6 +15,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class A {
diff --git a/LanguageFeatures/nnbd/late_A06_t04.dart b/LanguageFeatures/nnbd/late_A06_t04.dart
index 469cb90..066653a 100644
--- a/LanguageFeatures/nnbd/late_A06_t04.dart
+++ b/LanguageFeatures/nnbd/late_A06_t04.dart
@@ -17,6 +17,7 @@
  * @issue 39802
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A06_t05.dart b/LanguageFeatures/nnbd/late_A06_t05.dart
index 9d9883a..87cb83e 100644
--- a/LanguageFeatures/nnbd/late_A06_t05.dart
+++ b/LanguageFeatures/nnbd/late_A06_t05.dart
@@ -17,6 +17,7 @@
  * @issue 39802
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A06_t06.dart b/LanguageFeatures/nnbd/late_A06_t06.dart
index a0d9f69..bb316e2 100644
--- a/LanguageFeatures/nnbd/late_A06_t06.dart
+++ b/LanguageFeatures/nnbd/late_A06_t06.dart
@@ -16,6 +16,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class A {
diff --git a/LanguageFeatures/nnbd/late_A06_t07.dart b/LanguageFeatures/nnbd/late_A06_t07.dart
index ad8a644..3579cf1 100644
--- a/LanguageFeatures/nnbd/late_A06_t07.dart
+++ b/LanguageFeatures/nnbd/late_A06_t07.dart
@@ -15,6 +15,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class C {
diff --git a/LanguageFeatures/nnbd/late_A07_t01.dart b/LanguageFeatures/nnbd/late_A07_t01.dart
index 989ea38..a3f9022 100644
--- a/LanguageFeatures/nnbd/late_A07_t01.dart
+++ b/LanguageFeatures/nnbd/late_A07_t01.dart
@@ -14,6 +14,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class A {
diff --git a/LanguageFeatures/nnbd/late_A07_t02.dart b/LanguageFeatures/nnbd/late_A07_t02.dart
index e150800..fe7be16 100644
--- a/LanguageFeatures/nnbd/late_A07_t02.dart
+++ b/LanguageFeatures/nnbd/late_A07_t02.dart
@@ -14,6 +14,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 class A {
diff --git a/LanguageFeatures/nnbd/late_A08_t01.dart b/LanguageFeatures/nnbd/late_A08_t01.dart
index aee77b4..3fc6279 100644
--- a/LanguageFeatures/nnbd/late_A08_t01.dart
+++ b/LanguageFeatures/nnbd/late_A08_t01.dart
@@ -17,6 +17,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A08_t02.dart b/LanguageFeatures/nnbd/late_A08_t02.dart
index be94102..399e228 100644
--- a/LanguageFeatures/nnbd/late_A08_t02.dart
+++ b/LanguageFeatures/nnbd/late_A08_t02.dart
@@ -17,6 +17,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A08_t03.dart b/LanguageFeatures/nnbd/late_A08_t03.dart
index 7e81b0f..509eb9a 100644
--- a/LanguageFeatures/nnbd/late_A08_t03.dart
+++ b/LanguageFeatures/nnbd/late_A08_t03.dart
@@ -17,6 +17,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A08_t04.dart b/LanguageFeatures/nnbd/late_A08_t04.dart
index b4fb72d..badf45a 100644
--- a/LanguageFeatures/nnbd/late_A08_t04.dart
+++ b/LanguageFeatures/nnbd/late_A08_t04.dart
@@ -17,6 +17,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 String _log = "";
diff --git a/LanguageFeatures/nnbd/late_A08_t05.dart b/LanguageFeatures/nnbd/late_A08_t05.dart
index ac578fa..910a2d1 100644
--- a/LanguageFeatures/nnbd/late_A08_t05.dart
+++ b/LanguageFeatures/nnbd/late_A08_t05.dart
@@ -17,6 +17,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 const MAX = 10;
diff --git a/LanguageFeatures/nnbd/late_A08_t06.dart b/LanguageFeatures/nnbd/late_A08_t06.dart
index 4a1aa6c..c3995f0 100644
--- a/LanguageFeatures/nnbd/late_A08_t06.dart
+++ b/LanguageFeatures/nnbd/late_A08_t06.dart
@@ -17,6 +17,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
+// Requirements=nnbd-strong
 import "../../Utils/expect.dart";
 
 const MAX = 10;
diff --git a/LanguageFeatures/nnbd/late_A09_t01.dart b/LanguageFeatures/nnbd/late_A09_t01.dart
index 9ea9d82..60257e2 100644
--- a/LanguageFeatures/nnbd/late_A09_t01.dart
+++ b/LanguageFeatures/nnbd/late_A09_t01.dart
@@ -10,7 +10,7 @@
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
-import "../../Utils/expect.dart";
+// Requirements=nnbd-strong
 import "legacy_lib.dart";
 
 class X {