code: function mapper(fields, map) {
    var obj = {};
    fields.forEach((cur, i) => {
      let kv = pair(map[i], cur, i);
      obj[kv.name] = kv.value;
    });
    return obj;
  }
docs: /* Mapper: mapping fields with a specific map
  @param {array} fields
  @param {array} map
  @param {array} [{}, {}, {}, ...]