Default validation for updated properties

def _validation_error(prop, prop_type, prop_value, expected):
    """ Default validation for updated properties """

    if prop_type is None:
        attrib = 'value'
        assigned = prop_value
    else:
        attrib = 'type'
        assigned = prop_type

    raise ValidationError(
        'Invalid property {attrib} for {prop}:\n\t{attrib}: {assigned}\n\texpected: {expected}',
        attrib=attrib, prop=prop, assigned=assigned, expected=expected,
        invalid={prop: prop_value} if attrib == 'value' else {}
    )