Thus, a purchaser under a contract of sale, who at law is in possession as tenant at will of the vendor, has been held protected in respect of his equitable ownership as purchaser (Robertson v. Keith; Sandhurst Mutual Permanent Investment Building Society v. Gissing), a lessee in respect of an option of purchase contained in his lease (McMahon v. Swan) and a wife in respect of an equitable life interest claimed under an unsigned separation agreement made with her husband (Black v. Poole). A'Beckett J. decided the last named case in deference to previous decisions and against his own opinion, which he stated to be that 'those words were intended to refer to a tenancy as ordinarily understood arising out of an agreement under which the person in possession was allowed to occupy in consideration of some kind of rent or service of which the proprietor was to have the benefit.