Presumptions
4.—(1)  Whenever it is provided by this Act that the court may presume a fact, it may either regard such fact as proved unless and until it is disproved, or may call for proof of it.
(2)  Whenever it is directed by this Act that the court is to presume a fact, the court is to regard such fact as proved unless and until it is disproved.
(3)  When one fact is declared by this Act to be conclusive proof of another, the court is, on proof of the one fact, to regard the other as proved, and is not to allow evidence to be given for the purpose of disproving it.