code: public static short getDefaultReplication(FileSystem fs, Path path) {
      return (Short)
          (HadoopCompat.isVersion2x()
              ? invoke(GET_DEFAULT_REPLICATION_METHOD, fs, path)
              : invoke(GET_DEFAULT_REPLICATION_METHOD, fs));
    }
docs: This method invokes getDefaultReplication() without path on Hadoop 1 and
  with Path on Hadoop 2.
  
  Older versions of Hadoop 1 do not have
  {@link FileSystem#getDefaultReplication(Path)}. This api exists in Hadoop 2
  and recent versions of Hadoop 1. Path argument is required for viewfs filesystem
  in Hadoop 2. <p>