@Override
  public HadoopShims.HdfsEncryptionShim createHdfsEncryptionShim(FileSystem fs, Configuration conf) throws IOException {
    if (isHdfsEncryptionSupported()) {
      URI uri = fs.getUri();
      if ("hdfs".equals(uri.getScheme()) && fs instanceof DistributedFileSystem) {
        return HdfsEncryptionShim.createInstance(uri, conf);
      }
    }

    return new HadoopShims.NoopHdfsEncryptionShim();
  }
Compares two encryption key strengths.

@param zone1 First  EncryptionZone to compare
@param zone2 Second EncryptionZone to compare
@return 1 if zone1 is stronger; 0 if zones are equal; -1 if zone1 is weaker.
@throws IOException If an error occurred attempting to get key metadata
shims/0.23/src/main/java/org/apache/hadoop/hive/shims/Hadoop23Shims.java