Is a warranty made at the time of sale a warranty if it appears to have been intended and understood by the parties?

Also at p. 39: Any affirmance or representations made at the time of sale is a warranty if it appears to have been so intended and understood by the parties; and in determining whether it was so intended a decisive test is whether the vendor assumes to assert a fact of which the buyer is ignorant, or merely states an opinion on a matter of which the vendor has no special knowledge, and on which the buyer may be expected to exercise his own judgment. (De Lassalle v. Guildford [1901] 2 K.B. 215, 70 L.J.K.B. 533.) Nor is it necessary that the statement or representation should be simultaneous with the close of the bargain;