+ more test

pom.xml

@@ -241,5 +241,11 @@
             <version>33.2.0-jre</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>5.14.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>

src/test/java/conseq4j/execute/SequentialExecutorTest.java

@@ -0,0 +1,26 @@
+package conseq4j.execute;
+
+import static org.awaitility.Awaitility.await;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.BDDMockito.then;
+import static org.mockito.Mockito.spy;
+
+import java.util.concurrent.*;
+
+class SequentialExecutorTest {
+  @org.junit.jupiter.api.Test
+  void executeShouldDelegateToSubmit() {
+    SequentialExecutor sequentialExecutor = spy(new SequentialExecutor() {
+      @Override
+      public <T> Future<T> submit(Callable<T> task, Object sequenceKey) {
+        return CompletableFuture.completedFuture(null);
+      }
+    });
+
+    Future<Void> execute = sequentialExecutor.execute(() -> {}, "testKey");
+    await().until(execute::isDone);
+
+    then(sequentialExecutor).should().submit(any(Callable.class), eq("testKey"));
+  }
+}