Is it possible to override the utility function in erpnext?

1

Here i want to override the ‘validate_phone_number_with_country_code’

On custom doctype for one user of the workflow state should save any kind of data.
Then next state of user will modify the correct phone number.

Is it possible?

2

I don’t we can’t change the default behaviour,
so, I change the field to data. After other user I will throw validation error message from python