def get_existing_model(model_name):
    try:
        model_cls = engine.get_document_cls(model_name)
        log.debug('Model `{}` already exists. Using existing one'.format(
            model_name))
        return model_cls
    except ValueError:
        log.debug('Model `{}` does not exist'.format(model_name))
Gets the curent error message shown for the tab.
dataset/ETHPy150Open ramses-tech/ramses/ramses/models.py/get_existing_model--crossover with--dataset/ETHPy150Open rwl/muntjac/muntjac/ui/tab_sheet.py/ITab.getComponentError