Submit a recording to the database on write-math.com.

    Parameters
    ----------
    raw_data_json : str
        Raw data in JSON format

    Raises
    ------
    requests.exceptions.ConnectionError
        If the internet connection is lost.

def submit_recording(raw_data_json):
    """Submit a recording to the database on write-math.com.

    Parameters
    ----------
    raw_data_json : str
        Raw data in JSON format

    Raises
    ------
    requests.exceptions.ConnectionError
        If the internet connection is lost.
    """
    url = "http://www.martin-thoma.de/write-math/classify/index.php"
    headers = {'User-Agent': 'Mozilla/5.0',
               'Content-Type': 'application/x-www-form-urlencoded'}
    payload = {'drawnJSON': raw_data_json}

    s = requests.Session()
    req = requests.Request('POST', url, headers=headers, data=payload)
    prepared = req.prepare()
    s.send(prepared)