docs: def unregisterViewType(self, cls, window=None):
          """
          Unregisters the view at the given name.  If the window option is \
          supplied then the unregisterFromWindow method will be called for the \
          inputed class.
          
          :param          cls    | <subclass of XView>    
                          window | <QMainWindow> || <QDialog> || None
          
          :return     <bool> changed
          """
          if ( cls in self._viewTypes ):
              self._viewTypes.remove(cls)
              
              if ( window ):
                  cls.unregisterFromWindow(window)
                  
              return True
          return False