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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def convert_field(self, name, field):
 """ Convert a single field from a Peewee model field to a validator field. :param name: Name of the field as defined on this validator. :param name: Peewee field instance. :return: Validator field. """

        if PEEWEE3:
            field_type = field.field_type.lower()
        else:
            field_type = field.db_field

        pwv_field = ModelValidator.FIELD_MAP.get(field_type, StringField)

        print('pwv_field', field_type, pwv_field)

        validators = []
        required = not bool(getattr(field, 'null', True))
        choices = getattr(field, 'choices', ())
        default = getattr(field, 'default', None)
        max_length = getattr(field, 'max_length', None)
        unique = getattr(field, 'unique', False)

        if required:
            validators.append(validate_required())

        if choices:
            print('CHOICES', choices)
            validators.append(validate_one_of([c[0] for c in choices]))

        if max_length:
            validators.append(validate_length(high=max_length))

        if unique:
            validators.append(validate_model_unique(field, self.instance.select(), self.pk_field, self.pk_value))

        if isinstance(field, peewee.ForeignKeyField):
            if PEEWEE3:
                rel_field = field.rel_field
            else:
                rel_field = field.to_field
            return ModelChoiceField(field.rel_model, rel_field, default=default, validators=validators)

        if isinstance(field, ManyToManyField):
            return ManyModelChoiceField(
                field.rel_model, field.rel_model._meta.primary_key,
                default=default, validators=validators)

        return pwv_field(default=default, validators=validators)