Address code review

- Fix listeners initialization in CompositeRetryListener
- Fix mocking usage in MaxRetryAttemptsPolicyTests

Author: fmbenhassine

spring-core/src/main/java/org/springframework/core/retry/support/CompositeRetryListener.java

@@ -46,10 +46,11 @@ public CompositeRetryListener() {
 
 	/**
 	 * Create a new {@link CompositeRetryListener} with a list of delegates.
-	 * @param listeners the delegate listeners to register
+	 * @param listeners the delegate listeners to register. Must not be empty.
 	 */
 	public CompositeRetryListener(List<RetryListener> listeners) {
-		this.listeners = listeners;
+		Assert.notEmpty(listeners, "RetryListener List must not be empty");
+		this.listeners = List.copyOf(listeners);
 	}
 
 	/**

spring-core/src/test/java/org/springframework/core/retry/support/MaxRetryAttemptsPolicyTests.java

@@ -17,12 +17,12 @@
 package org.springframework.core.retry.support;
 
 import org.junit.jupiter.api.Test;
-import org.mockito.Mockito;
 
 import org.springframework.core.retry.RetryExecution;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link MaxRetryAttemptsPolicy}.
@@ -35,15 +35,16 @@ class MaxRetryAttemptsPolicyTests {
 	void testDefaultMaxRetryAttempts() {
 		// given
 		MaxRetryAttemptsPolicy retryPolicy = new MaxRetryAttemptsPolicy();
+		Throwable throwable = mock();
 
 		// when
 		RetryExecution retryExecution = retryPolicy.start();
 
 		// then
-		assertThat(retryExecution.shouldRetry(Mockito.any(Exception.class))).isTrue();
-		assertThat(retryExecution.shouldRetry(Mockito.any(Exception.class))).isTrue();
-		assertThat(retryExecution.shouldRetry(Mockito.any(Exception.class))).isTrue();
-		assertThat(retryExecution.shouldRetry(Mockito.any(Exception.class))).isFalse();
+		assertThat(retryExecution.shouldRetry(throwable)).isTrue();
+		assertThat(retryExecution.shouldRetry(throwable)).isTrue();
+		assertThat(retryExecution.shouldRetry(throwable)).isTrue();
+		assertThat(retryExecution.shouldRetry(throwable)).isFalse();
 	}
 
 	@Test