code: async function pakoUnzip(inputData) {
    let strm
    let pos = 0
    let i = 0
    const chunks = []
    let inflator
    do {
      const remainingInput = inputData.slice(pos)
      inflator = new Inflate()
      strm = inflator.strm
      inflator.push(remainingInput, Z_SYNC_FLUSH)
      if (inflator.err) throw new Error(inflator.msg)
  
      pos += strm.next_in
      chunks[i] = Buffer.from(inflator.result)
      i += 1
    } while (strm.avail_in)
  
    const result = Buffer.concat(chunks)
    return result
  }
docs: browserify-zlib, which is the zlib shim used by default in webpacked code, does not properly uncompress bgzf chunks that contain more than one bgzf block, so export an unzip function that uses pako directly if we are running in a browser.