private FileSystem maybeWrapFileSystem(FileSystem base, Configuration conf) {
    try {
      Class<?> clazz = conf.getClass("hbase.fs.wrapper", null);
      if (clazz != null) {
        return (FileSystem) clazz.getConstructor(FileSystem.class, Configuration.class)
          .newInstance(base, conf);
      }
    } catch (Exception e) {
      LOG.error("Failed to wrap filesystem: " + e);
    }
    return base;
  }
Returns an instance of Filesystem wrapped into the class specified in hbase.fs.wrapper
property, if one is set in the configuration, returns unmodified FS instance passed in as an
argument otherwise.
@param base Filesystem instance to wrap
@param conf Configuration
@return wrapped instance of FS, or the same instance if no wrapping configured.
hbase-server/src/main/java/org/apache/hadoop/hbase/fs/HFileSystem.java