code: public ResourceGroupInner update(String resourceGroupName, ResourceGroupPatchable parameters) {
          return updateWithServiceResponseAsync(resourceGroupName, parameters).toBlocking().single().body();
      }
docs: Updates a resource group.
  Resource groups can be updated through a simple PATCH operation to a group address. The format of the request is the same as that for creating a resource group. If a field is unspecified, the current value is retained.
  
  @param resourceGroupName The name of the resource group to update. The name is case insensitive.
  @param parameters Parameters supplied to update a resource group.
  @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 ResourceGroupInner object if successful.