Create order instructions to place an order at exchange.
    :param str order_type: define type of order to place.
    :param int selection_id: selection on which to place order
    :param float handicap: handicap if placing order on asianhandicap type market
    :param str side: side of order
    :param resources.LimitOrder limit_order: if orderType is a limitOrder structure details of the order.
    :param resources.LimitOnCloseOrder limit_on_close_order: if orderType is a
    limitOnCloseOrder structure details of the order.
    :param resources.MarketOnCloseOrder market_on_close_order: if orderType is
    a marketOnCloseOrder structure details of the order.
    :param str customer_order_ref: an optional reference customers can set to identify instructions..

    :return: orders to place.
    :rtype: dict

def place_instruction(order_type, selection_id, side, handicap=None, limit_order=None, limit_on_close_order=None,
                      market_on_close_order=None, customer_order_ref=None):
    """
    Create order instructions to place an order at exchange.
    :param str order_type: define type of order to place.
    :param int selection_id: selection on which to place order
    :param float handicap: handicap if placing order on asianhandicap type market
    :param str side: side of order
    :param resources.LimitOrder limit_order: if orderType is a limitOrder structure details of the order.
    :param resources.LimitOnCloseOrder limit_on_close_order: if orderType is a
    limitOnCloseOrder structure details of the order.
    :param resources.MarketOnCloseOrder market_on_close_order: if orderType is
    a marketOnCloseOrder structure details of the order.
    :param str customer_order_ref: an optional reference customers can set to identify instructions..

    :return: orders to place.
    :rtype: dict
    """

    args = locals()
    return {
        to_camel_case(k): v for k, v in args.items() if v is not None
    }