我想在我的flink作业（scala）中使用内存缓存，这样我就可以为密钥设置ttl（生存时间）。我一直在寻找解决办法，找到了Guava。但是，我不确定它是否适用于flink（v1.6.3-scala），因为我无法在flinkshell中加载任何版本的guava。

scala> :require flink-shaded-guava-18.0-6.0.jar
The path 'flink-shaded-guava-18.0-6.0.jar' cannot be loaded, because existing classpath entries conflict.

scala> :require flink-shaded-guava-18.0-5.0.jar
The path 'flink-shaded-guava-18.0-5.0.jar' cannot be loaded, because existing classpath entries conflict.

scala> :require flink-shaded-guava-18.0-4.0.jar
The path 'flink-shaded-guava-18.0-4.0.jar' cannot be loaded, because existing classpath entries conflict.

scala> :require flink-shaded-guava-18.0-3.0.jar
The path 'flink-shaded-guava-18.0-3.0.jar' cannot be loaded, because existing classpath entries conflict.

scala> :require flink-shaded-guava-18.0-2.0.jar
The path 'flink-shaded-guava-18.0-2.0.jar' cannot be loaded, because existing classpath entries conflict.

scala> :require flink-shaded-guava-18.0-1.0.jar
The path 'flink-shaded-guava-18.0-1.0.jar' cannot be loaded, because existing classpath entries conflict.

有别的选择吗？对解决这个错误有帮助吗？