[objc] Clarify (with comment) that the `_object` field (even if public) is off limit (#264)
[objc] Clarify (with comment) that the `_object` field (even if public) is off limit (#264)


jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000