How does NotNull work on CI - is it checked?

Author: MarcellPerger1

src/test/java/net/marcellperger/mathexpr/util/rs/ResultTest.java

@@ -2,6 +2,7 @@
 
 import net.marcellperger.mathexpr.util.rs.Result.Ok;
 import net.marcellperger.mathexpr.util.rs.Result.Err;
+import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -430,4 +431,17 @@ void errOpt() {
         assertEquals(Optional.empty(), getOk().errOpt());
         assertEquals(Optional.of(new Err<>("TESTING_ERROR")), getErr().errOpt());
     }
+
+    void x(@NotNull Object arg) {
+        System.out.println("arg = " + arg);
+    }
+    @Test
+    void whatDoesNotNullDoOnCI() {
+        try {
+            x(null);
+        } catch (IllegalArgumentException e) {
+            fail("It checks for @NotNull", e);
+        }
+        fail("It does not check @NotNull");
+    }
 }