Looks up the view type based on the inputed view type name.
        
        :param      viewTypeName | <str>

def findViewType(self, viewTypeName):
        """
        Looks up the view type based on the inputed view type name.
        
        :param      viewTypeName | <str>
        """
        for viewType in self._viewTypes:
            if ( viewType.viewTypeName() == viewTypeName ):
                return viewType
        return None