code: public ServiceFuture<String> getMetadataAsync(String scope, final ServiceCallback<String> serviceCallback) {
          return ServiceFuture.fromResponse(getMetadataWithServiceResponseAsync(scope), serviceCallback);
      }
docs: Gets OData metadata XML document.
  
  @param scope A valid scope, i.e. management group, subscription, resource group, or resource ID. Scope used has no effect on metadata returned.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object