Strengthen graal incubating-not-found test to detect incubator API on classpath

integration-tests/graal/src/test/java/io/opentelemetry/integrationtests/graal/IncubatingNotFoundApiTests.java

@@ -7,20 +7,24 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import io.opentelemetry.api.logs.Logger;
 import io.opentelemetry.api.logs.LoggerProvider;
-import io.opentelemetry.api.metrics.LongCounterBuilder;
 import io.opentelemetry.api.metrics.MeterProvider;
-import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.api.trace.TracerProvider;
 import org.junit.jupiter.api.Test;
 
 class IncubatingNotFoundApiTests {
   @Test
   void incubatingApiIsNotFoundViaReflection() {
-    assertThat(LoggerProvider.noop().get("test")).isInstanceOf(Logger.class);
-    assertThat(TracerProvider.noop().get("test")).isInstanceOf(Tracer.class);
-    assertThat(MeterProvider.noop().get("test").counterBuilder("test"))
-        .isInstanceOf(LongCounterBuilder.class);
+    // The graal module deliberately excludes :api:incubator, so the noop instances must come from
+    // the stable api packages, not io.opentelemetry.api.incubator.*. An isInstanceOf check against
+    // the stable types cannot detect a regression here because the incubator Extended* types
+    // subtype the stable types; assert on the runtime class package instead, since the Extended*
+    // types are not on this module's classpath to reference directly.
+    assertThat(LoggerProvider.noop().get("test").getClass().getName())
+        .doesNotStartWith("io.opentelemetry.api.incubator.");
+    assertThat(TracerProvider.noop().get("test").getClass().getName())
+        .doesNotStartWith("io.opentelemetry.api.incubator.");
+    assertThat(MeterProvider.noop().get("test").counterBuilder("test").getClass().getName())
+        .doesNotStartWith("io.opentelemetry.api.incubator.");
   }
 }