fnSetupNewMockServer = function () {
		// clean up previous mock server
		if (oMockServer) {
			oMockServer.stop();
			oMockServer.destroy();
		}

		//Initialize mock servers
		oMockServer = new MockServer({
			rootUri: sServiceUrl
		});
		oMockServer.simulate("test-resources/sap/ui/core/qunit/model/metadata_orgHierarchy.xml", "test-resources/sap/ui/core/qunit/model/orgHierarchy/");
		oMockServer.start();
	}
Creates a new Mock-Server, this makes sure that after deleting nodes the original data-set is restored.
Called in the setup step of each test-module.