import java.util.concurrent.atomic.AtomicLong;
import org.springframework.messaging.Message;
import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
import org.springframework.messaging.simp.SimpMessageType;
import org.springframework.messaging.support.MessageHeaderAccessor;
<BUG>import org.springframework.util.Assert;
</BUG>
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
import org.springframework.util.StringUtils;

import java.util.concurrent.atomic.AtomicLong;
import org.springframework.messaging.Message;
import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
import org.springframework.messaging.simp.SimpMessageType;
import org.springframework.messaging.support.MessageHeaderAccessor;
import org.springframework.util.ClassUtils;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
import org.springframework.util.StringUtils;
