missing shouldBeginSignUp hook

[skywalkerlw]

In iOS, we have following callback which could be used to do some pre check :

• (BOOL)signUpViewController:(PFSignUpViewController *)signUpController shouldBeginSignUp:(NSDictionary *)info

Is there any similar one on Android SDK?

The background in my app is I need to pre check the validity on the Parse account, since its user name will later be used as the AWS bucket name while there're some restrictions on bucket naming. For example, AWS buckets names do not allow space characters.