Use AssertionsForClassType

core/src/test/java/org/springframework/security/concurrent/AbstractDelegatingSecurityContextScheduledExecutorServiceTests.java

@@ -15,7 +15,7 @@
  */
 package org.springframework.security.concurrent;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;