(1) A registered society which has as one of its objects the marketing of any article or produce obtained by the work or industry of its members may by its by-laws or otherwise, contract with its members—
(a) that every such member who produces any such article shall market the whole or any specified amount, portion or description thereof to or through the society;
(b) that any member who is proved or adjudged to have contravened the by-laws or to have acted in breach of the contract shall pay to the society liquidated damages in a sum ascertained or assessed in such a manner as may be prescribed in the by-laws.
(2) A contract entered into under this section shall not be questioned in any court on the ground only that it is a contract in restraint of trade.