mozilla/browserid — comment on commit e064ab3bcd9e1ab6a93db7e60ec5496b7f5b1421
File: resources/static/shared/user.js line 124
By shane-tomlinson:

@lloyd - addressCache is initialized before anything else in that file is run. It is not even possible to run any functions that user.js exposes until addressCache is initialized because BrowserID.User will not yet be defined.