code: public static UnderFileSystemBlockReader create(UnderFileSystemBlockMeta blockMeta, long offset,
        BlockStore localBlockStore, UfsManager ufsManager, UfsInputStreamManager ufsInstreamManager)
        throws IOException {
      UnderFileSystemBlockReader ufsBlockReader =
          new UnderFileSystemBlockReader(blockMeta, localBlockStore, ufsManager, ufsInstreamManager);
      ufsBlockReader.init(offset);
      return ufsBlockReader;
    }
docs: Creates an instance of {@link UnderFileSystemBlockReader} and initializes it with a reading
  offset.
  
  @param blockMeta the block meta
  @param offset the position within the block to start the read
  @param localBlockStore the Local block store
  @param ufsManager the manager of ufs
  @param ufsInstreamManager the manager of ufs instreams
  @return the block reader