code: public Observable<Page<LabAccountInner>> listAsync(final String expand, final String filter, final Integer top, final String orderby) {
          return listWithServiceResponseAsync(expand, filter, top, orderby)
              .map(new Func1<ServiceResponse<Page<LabAccountInner>>, Page<LabAccountInner>>() {
                  @Override
                  public Page<LabAccountInner> call(ServiceResponse<Page<LabAccountInner>> response) {
                      return response.body();
                  }
              });
      }
docs: List lab accounts in a subscription.
  
  @param expand Specify the $expand query. Example: 'properties($expand=sizeConfiguration)'
  @param filter The filter to apply to the operation.
  @param top The maximum number of resources to return from the operation.
  @param orderby The ordering expression for the results, using OData notation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;LabAccountInner&gt; object