'call the method get_empty_list_help of the model and set the window action help message'

@api.multi
def read(self, fields=None, load='_classic_read'):

    result = super(IrActionsActWindow, self).read(fields, load=load)
    if ((not fields) or ('help' in fields)):
        for values in result:
            model = values.get('res_model')
            if (model in self.env):
                values['help'] = self.env[model].get_empty_list_help(values.get('help', ''))
    return result
