code: public Observable<SignalRKeysInner> listKeysAsync(String resourceGroupName, String resourceName) {
          return listKeysWithServiceResponseAsync(resourceGroupName, resourceName).map(new Func1<ServiceResponse<SignalRKeysInner>, SignalRKeysInner>() {
              @Override
              public SignalRKeysInner call(ServiceResponse<SignalRKeysInner> response) {
                  return response.body();
              }
          });
      }
docs: Get the access keys of the SignalR resource.
  
  @param resourceGroupName The name of the resource group that contains the resource. You can obtain this value from the Azure Resource Manager API or the portal.
  @param resourceName The name of the SignalR resource.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the SignalRKeysInner object