     @_logger.debug @_customParams.query, 'Setting \'filter\' parameter'
     this
 
+  ###*
+   * Define a {Filter} (applied to query result) 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.query` search parameter.
+   * @return {ProductProjectionService} Chained instance of this class
+  ###
   filterByQuery: (filter) ->
     return this unless filter
     encodedFilter = encodeURIComponent(filter)

    @_logger.debug @_customParams.query, 'Setting \'filter.facets\' parameter'
    this

  facet: (facet) ->
    return this unless facet
    encodedFacet = encodeURIComponent(facet)

    _.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: ->
