framework/application/engine/api/src/main/java/org/ldp4j/application/engine/ApplicationEngine.java
private static ApplicationEngine findDelegate() {
		try {
			ApplicationEngine result=createApplicationEngineFromSPI();
			if(result==null) {
				result=createApplicationEngineFromConfigurationFile();
			}

			if(result==null) {
				final String delegateClassName = System.getProperty(LDP4J_APPLICATION_ENGINE_PROPERTY);
				if(delegateClassName!=null) {
					result=createApplicationEngineForClassName(delegateClassName);
				}
			}

			return result;
		} catch (final Exception ex) {
			throw new IllegalStateException("Could not find application engine",ex);
		}
	}
private static ApplicationEngine findDelegate() {
		try {
			ApplicationEngine result=createApplicationEngineFromSPI();
			if(result==null) {
				result=createApplicationEngineFromConfigurationFile();
			}

			if(result==null) {
				final String delegateClassName = System.getProperty(LDP4J_APPLICATION_ENGINE_PROPERTY);
				if(delegateClassName!=null) {
					result=createApplicationEngineForClassName(delegateClassName);
				}
			}

			return result;
		} catch (final Exception ex) {
			throw new IllegalStateException("Could not find application engine",ex);
		}
	}
Obtain an {@code ApplicationEngine} instance using the method described
in {@link ApplicationEngine#engine()}.

@return an instance of {@code ApplicationEngine} if available, or null if
a default implementation class is to be selected.