code: public Observable<Page<RecommendationInner>> listRecommendedRulesForWebAppAsync(final String resourceGroupName, final String siteName, final Boolean featured, final String filter) {
          return listRecommendedRulesForWebAppWithServiceResponseAsync(resourceGroupName, siteName, featured, filter)
              .map(new Func1<ServiceResponse<Page<RecommendationInner>>, Page<RecommendationInner>>() {
                  @Override
                  public Page<RecommendationInner> call(ServiceResponse<Page<RecommendationInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Get all recommendations for an app.
  Get all recommendations for an app.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param siteName Name of the app.
  @param featured Specify &lt;code&gt;true&lt;/code&gt; to return only the most critical recommendations. The default is &lt;code&gt;false&lt;/code&gt;, which returns all recommendations.
  @param filter Return only channels specified in the filter. Filter is specified by using OData syntax. Example: $filter=channels eq 'Api' or channel eq 'Notification'
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;RecommendationInner&gt; object