config/src/main/java/org/springframework/security/config/annotation/web/configurers/LogoutConfigurer.java
private LogoutSuccessHandler getLogoutSuccessHandler() {
		LogoutSuccessHandler handler = this.logoutSuccessHandler;
		if (handler == null) {
			handler = createDefaultSuccessHandler();
		}
		return handler;
	}
private LogoutSuccessHandler getLogoutSuccessHandler() {
		LogoutSuccessHandler handler = this.logoutSuccessHandler;
		if (handler == null) {
			handler = createDefaultSuccessHandler();
		}
		return handler;
	}
Gets the {@link LogoutSuccessHandler} if not null, otherwise creates a new
{@link SimpleUrlLogoutSuccessHandler} using the {@link #logoutSuccessUrl(String)}.

@return the {@link LogoutSuccessHandler} to use