n2 See Goble v. Dotson (1962) 203 Cal.App.2d 272 [21 Cal.Rptr. 769], where the deed given by a real estate developer to the plaintiffs contained a condition that grantees would not build a pier or boathouse. Despite this reference in the deed to the subject of berthing for boats, the court allowed plaintiffs to prove by parol evidence that the condition was agreed to in return for the developer's oral promise that plaintiffs were to have the use of two boat spaces nearby.