docs: private VectorClock readVersion() {
          try {
  
              if(this.cachedVersion == null) {
                  File versionFile = getVersionFile();
                  if(versionFile.exists()) {
                      // read the version file and return version.
                      String hexCode = FileUtils.readFileToString(versionFile, "UTF-8");
                      this.cachedVersion = new VectorClock(Hex.decodeHex(hexCode.toCharArray()));
                  }
              }
              return this.cachedVersion;
          } catch(Exception e) {
              throw new VoldemortException("Failed to read Version for file :" + getName(), e);
          }
      }