code: public Observable<Page<ProviderInner>> listAsync(final Integer top, final String expand) {
          return listWithServiceResponseAsync(top, expand)
              .map(new Func1<ServiceResponse<Page<ProviderInner>>, Page<ProviderInner>>() {
                  @Override
                  public Page<ProviderInner> call(ServiceResponse<Page<ProviderInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Gets all resource providers for a subscription.
  
  @param top The number of results to return. If null is passed returns all deployments.
  @param expand The properties to include in the results. For example, use &amp;$expand=metadata in the query string to retrieve resource provider metadata. To include property aliases in response, use $expand=resourceTypes/aliases.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;ProviderInner&gt; object