I want the browser SDK to expose a stateful Identify builder that I can construct with new…

I want the browser SDK to expose a stateful Identify builder that I can construct with new…: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). The builder should support set(property, value) , setOnce(property, value) , add(property, value) , append(property, value)…