in core/src/main/java/org/apache/sling/testing/mock/sling/context/SlingContextImpl.java [123:139]
    protected void setUp() {
        super.setUp();
        MockSling.setAdapterManagerBundleContext(bundleContext());
        if (this.resourceResolverFactoryActivatorProps != null) {
            // use OSGi ConfigurationAdmin to pass over customized configuration to Resource Resolver Factory Activator service
            MockOsgi.setConfigForPid(bundleContext(), RESOURCERESOLVERFACTORYACTIVATOR_PID, this.resourceResolverFactoryActivatorProps);
        }
        // automatically register resource resolver factory when ResourceResolverType != NONE,
        // so the ResourceResolverFactory is available as OSGi service immediately
        if (resourceResolverType != ResourceResolverType.NONE) {
            resourceResolverFactory();
        }
        registerDefaultServices();
    }