private String deployDirCommand() throws IOException {
    ClassBuilder classBuilder = new ClassBuilder();
    File jarsDir = folderRule.getFolder().toPath().toFile();
    String jarName1 = "DeployCommandsDUnit1.jar";
    File jar1 = new File(jarsDir, jarName1);
    String class1 = "DeployCommandsDUnitA";
    classBuilder.writeJarFromName(class1, jar1);
    return "deploy --dir=" + jarsDir.getAbsolutePath();
  }
This test iterates through the versions of Geode and executes client compatibility with
the current version of Geode.
geode-assembly/src/upgradeTest/java/org/apache/geode/management/RollingUpgradeWithGfshDUnitTest.java