in lib/nano.js [1093:1104]
    function partitionedFind (partition, query, callback) {
      if (missing(partition, query) || typeof query !== 'object') {
        return callbackOrRejectError(callback)
      }
      return relax({
        db: dbName,
        path: '_partition/' + encodeURIComponent(partition) + '/_find',
        method: 'POST',
        body: query
      }, callback)
    }