def contribute_to_class(self, process, fields, name):
        """Register this field with a specific process.

        :param process: Process descriptor instance
        :param fields: Fields registry to use
        :param name: Field name
        """
        # Use order-preserving definition namespace (__dict__) to respect the
        # order of GroupField's fields definition.
        for field_name in self.field_group.__dict__:
            if field_name.startswith('_'):
                continue

            field = getattr(self.field_group, field_name)
            field.contribute_to_class(process, self.fields, field_name)

        super().contribute_to_class(process, fields, name)