code: public PagedList<RoleInner> listByDataBoxEdgeDevice(final String deviceName, final String resourceGroupName) {
          ServiceResponse<Page<RoleInner>> response = listByDataBoxEdgeDeviceSinglePageAsync(deviceName, resourceGroupName).toBlocking().single();
          return new PagedList<RoleInner>(response.body()) {
              @Override
              public Page<RoleInner> nextPage(String nextPageLink) {
                  return listByDataBoxEdgeDeviceNextSinglePageAsync(nextPageLink).toBlocking().single().body();
              }
          };
      }
docs: Lists all the roles configured in a data box edge/gateway device.
  
  @param deviceName The device name.
  @param resourceGroupName The resource group name.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the PagedList&lt;RoleInner&gt; object if successful.