!str #19710 Use Java types in Attributes Java API

akka-stream-tests/src/test/java/akka/stream/javadsl/AttributesTest.java

@@ -7,6 +7,7 @@ import static org.junit.Assert.assertEquals;
 
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.Optional;
 
 import org.junit.ClassRule;
 import org.junit.Test;
@@ -47,4 +48,32 @@ public class AttributesTest extends StreamTest {
       attributes.getAttribute(Attributes.Name.class, new Attributes.Name("default")));
   }
 
+  @Test
+  public void mustGetMissingAttributeByClass() {
+    assertEquals(
+        Optional.empty(),
+        attributes.getAttribute(Attributes.LogLevels.class));
+  }
+
+  @Test
+  public void mustGetPossiblyMissingAttributeByClass() {
+    assertEquals(
+        Optional.of(new Attributes.Name("b")),
+        attributes.getAttribute(Attributes.Name.class));
+  }
+
+  @Test
+  public void mustGetPossiblyMissingFirstAttributeByClass() {
+    assertEquals(
+        Optional.of(new Attributes.Name("a")),
+        attributes.getFirstAttribute(Attributes.Name.class));
+  }
+
+  @Test
+  public void mustGetMissingFirstAttributeByClass() {
+    assertEquals(
+        Optional.empty(),
+        attributes.getFirstAttribute(Attributes.LogLevels.class));
+  }
+
 }