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

  ###
  @baseResourceEndpoint: '/product-projections'

  _setDefaults: ->
    super()
    @_customParams =

        facet: []

  ###*
   * Define whether to query for staged or current product projection.
   * @param Boolean [staged] true to query staged products (default). False to query published products
   * @return {ProductProjectionService} Chained instance of this class
  ###
