docs: function hasLegacy (hashes) {
        var ary = Object.keys(hashes).filter(function (k) {
          return hashes[k] < 0
        })
        if(ary.length)
          peer.blobs.has(ary, function (err, haves) {
            if(err) drain.abort(err) //ERROR: abort this stream.
            else haves.forEach(function (have, i) {
              if(have) has(peer.id, ary[i], have)
            })
          })
      }