To show/search on properties that are for sale only, forSale must be set to True, which is the default value.
Setting it to False will return only properties that are not for sale. If viewing properties that are not for sale, you can set lastSoldDate, lastSoldPrice, or both.
lastSoldDate returns/searches on properties that were sold up to a the entered date.
lastSoldPrice searches on properties sold for the specified price.