def mentions(text, gcube_token=None, lang=DEFAULT_LANG, api=DEFAULT_SPOT_API):
    '''
    Find possible mentions in a text, do not link them to any entity.
    :param text: the text where to find mentions.
    :param gcube_token: the authentication token provided by the D4Science infrastructure.
    :param lang: the Wikipedia language.
    :param api: the API endpoint.
    '''
    payload = [("text", text.encode("utf-8")),
               ("lang", lang.encode("utf-8"))]
    json_response = _issue_request(api, payload, gcube_token)
    return MentionsResponse(json_response) if json_response else None
Find possible mentions in a text, do not link them to any entity.
    :param text: the text where to find mentions.
    :param gcube_token: the authentication token provided by the D4Science infrastructure.
    :param lang: the Wikipedia language.
    :param api: the API endpoint.