     @_logger.debug @_customParams.query, 'Setting \'filter.facets\' parameter'
     this
 
+  ###*
+   * Define a {Facet} used for calculating statistical counts for searched product projections.
+   * @link http://commercetools.de/dev/http-api-projects-products.html#search-facets
+   * @param {String} [facet] A {Facet} string for the `facet` search parameter.
+   * @return {ProductProjectionService} Chained instance of this class
+  ###
   facet: (facet) ->
     return this unless facet
     encodedFacet = encodeURIComponent(facet)

        facet: []

  ###*
   * Define to fetch only staged products
   * @param Boolean [staged] true to query staged products (default). False to query published products
   * @return {ProductProjectionService} Chained instance of this class
  ###

    _.compact([super()].concat(customQueryString)).join '&'

  ###*
   * Search product projections with search parameters
   * @return {Promise} A promise, fulfilled with an {Object} or rejected with a {SphereError}
  ###
  search: ->
