def METHOD_NAME(self, query: List[str], add_eos: bool = True):
    """
    Add documents to the Faiss index
    Args:
        docs: List[str], list of documents that is going to be added to the index
        add_eos: bool, whether add the eos in the end
    """
    output = 'success'
    if not self.updatable:
        if not self.updatable:
            return 'no dynamic service, no action is performed'
    for i, service in enumerate(self.retrieval_services):
        if service.updatable:
            service.METHOD_NAME(query, add_eos)
    return output