Function: setAllowedBroker(byte[32] _brokerHash, bool _allowed)
This allows the owner of the contract to add new _brokerHash to the allowedBrokerSet or remove the existed.
setAllowedBroker(byte[32] _brokerHash, bool _allowed)This allows the owner of the contract to add new _brokerHash to the allowedBrokerSet or remove the existed.