Use AssertJ's isEmpty() instead of hasSize(0)

Achieved via global search-and-replace.

spring-context-support/src/test/java/org/springframework/cache/jcache/interceptor/CacheRemoveAllOperationTests.java

@@ -42,7 +42,7 @@ public class CacheRemoveAllOperationTests extends AbstractCacheOperationTests<Ca
 		CacheRemoveAllOperation operation = createSimpleOperation();
 
 		CacheInvocationParameter[] allParameters = operation.getAllParameters();
-		assertThat(allParameters).hasSize(0);
+		assertThat(allParameters).isEmpty();
 	}
 
 }