code: public ServiceFuture<NetworkSecurityGroupInner> getByResourceGroupAsync(String resourceGroupName, String networkSecurityGroupName, final ServiceCallback<NetworkSecurityGroupInner> serviceCallback) {
          return ServiceFuture.fromResponse(getByResourceGroupWithServiceResponseAsync(resourceGroupName, networkSecurityGroupName), serviceCallback);
      }
docs: Gets the specified network security group.
  
  @param resourceGroupName The name of the resource group.
  @param networkSecurityGroupName The name of the network security group.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object