Thanks for your reply. I had a feeling that it was a mandatory parameter for the constructor. I have also tried creating "sap.ui.core.mvc.JSview" but I get an "Unable to get property 'viewData' of undefined or null reference" error. And "sap.ui.jsview" also doesn't work.
var lco_View = new sap.ui.core.mvc.JSView("Tasks");
lco_View.setViewName("zbc_ui5_app01.Tasks");
lco_MasterShell.addContent(lco_View);
Thanks