'If the field has \'required_if_provider="<provider>"\' attribute, then it
required if record.provider is <provider>.'

@api.multi
def _check_required_if_provider(self):

    for acquirer in self:
        if any((((getattr(f, 'required_if_provider', None) == acquirer.provider) and (not acquirer[k])) for (k, f) in self._fields.items())):
            return False
    return True
