title: How do I unit-test saving file to the disk with FileUtils?
body: <p>I know this variation has been asked before. </p>
  
  <p>But, One of my functions is using <a href="https://commons.apache.org/proper/commons-io/javadocs/api-1.4/org/apache/commons/io/FileUtils.html#writeStringToFile(java.io.File,%20java.lang.String)" rel="nofollow noreferrer">Common's FileUtils</a>. Here, it only takes File object and String. Is there any way to unit test this?</p>