code: private static RuntimeInstance findDelegate() {
  		try {
  			RuntimeInstance result=createRuntimeInstanceFromSPI();
  			if(result==null) {
  				result=createRuntimeInstanceFromConfigurationFile();
  			}
  
  			if(result==null) {
  				final String delegateClassName = System.getProperty(RDF_API_SPI_PROPERTY);
  				if(delegateClassName!=null) {
  					result=createRuntimeInstanceForClassName(delegateClassName);
  				}
  			}
  
  			if(result==null) {
  				result=new DefaultRuntimeInstance();
  			}
  
  			return result;
  		} catch (final Exception ex) {
  			throw new IllegalStateException("Could not find runtime delegate",ex);
  		}
  	}
docs: Obtain a {@code RuntimeInstance} instance using the method described in
  {@link #getInstance}.
  
  @return an instance of {@code RuntimeInstance}.