code: function HashFile(hA = 'sha256', bS = 1048576) {
  
      hashAlgorithm = hA;
      blockSize = bS;
  
      chunker = new SizeChunker({
          chunkSize: blockSize,
          flushTail: true
      });
  }
docs: Constructor for the reader. This initializes the settings for hashing a file,
  so the hashBlocks() function can be reused on different files.
  
  @param {String} hA The hash function to be used
  @param {Integer} bS The block size in bytes; the default value is 1 MiB. Each of
  the blocks becomes a leaf in the Merkle Tree