code: public void registerServiceConfiguration(String id, String configFile,
  			DescribeService service) throws POIProxyException {
  		if (service == null || configFile == null || service.getId() == null) {
  			throw new POIProxyException("Null service configuration");
  		}
  
  		this.registeredConfigurations.put(id, configFile);
  		this.parsedConfigurations.put(id, service);
  
  		try {
  			this.save(id, configFile);
  		} catch (IOException e) {
  			throw new POIProxyException("Unable to write service configuration");
  		}
  	}
docs: Registers a new service into the library
  
  @param id
  The id of the service
  @param configFile
  The content of the json document describing the service
  @param describeService
  The parsed {@link DescribeService}
  @throws POIProxyException
  When any of the parameters is null