decompress = array => {
  if (!array.length) {
    return '';
  } else if (array.length === 1) {
    throw new Error(
      'Compressed array must be either empty ' + 'or at least 2 blocks big.'
    );
  }

  const padding = new Array(MAX_BLOCK_SIZE + 1).join(0);

  let string = array
    .slice(0, -2)
    .map(block => (padding + (block >>> 0).toString(2)).slice(-padding.length))
    .join('');

  // Append the last block.
  const lastBlockSize = array.slice(-1)[0];
  const lastBlock = array.slice(-2)[0];
  string += (padding + (lastBlock >>> 0).toString(2)).slice(-lastBlockSize);

  return string;
}
Decompress int32 array back to 0-1 string.

@param {number[]} array
@return {string}