code: function mergeQuery(path, newQuery) {
      let parsed, properties, query, queryString;
      // Return the original path if the query to merge is empty.
      if (Object.keys(newQuery).length === 0) {
          return path;
      }
      // Parse the original path.
      parsed = url.parse(path, true);
      // Merge the queries to form a new query.
      query = parsed.query;
      properties = Object.keys(newQuery);
      for (let i = 0, u = properties.length; i < u; ++i) {
          let property = properties[i];
          query[property] = newQuery[property];
      }
      queryString = querystring.stringify(query);
      path = parsed.pathname + '?' + queryString;
      return path;
  }
docs: Merge additional query parameters onto an existing request path and return
  the combined path + query
  
  @param {string} path Request path, with or without a query
  @param {Object} newQuery Query parameters to merge
  @return {string} New path with query parameters merged