No instruction on `private fun signIn` in SignInActivity.kt

[petestmart]

In the SignInActivity.kt file there is a private fun signIn() function between the onStart function and the onSignInResult function that has a TODO that reads // TODO: implement:

private fun signIn() { // TODO: implement }

I see no instruction for this line of code and I am unable to create an account in the app. I'm assuming this has something to do with it. This function is also missing from the build-android finished project.