def make_payload(base, method, params):
    """Build Betfair JSON-RPC payload.

    :param str base: Betfair base ("Sports" or "Account")
    :param str method: Betfair endpoint
    :param dict params: Request parameters
    """
    payload = {
        'jsonrpc': '2.0',
        'method': '{base}APING/v1.0/{method}'.format(**locals()),
        'params': utils.serialize_dict(params),
        'id': 1,
    }
    return payload
Build Betfair JSON-RPC payload.

    :param str base: Betfair base ("Sports" or "Account")
    :param str method: Betfair endpoint
    :param dict params: Request parameters