def validate_uri(self):
        uri = rfc3986.uri_reference(self.identifier)
        valid_uri_scheme = uri.scheme in self.allowed_schemes
        return uri.is_valid() and valid_uri_scheme and uri.is_absolute()
Specification URIs have to be valid, have a scheme and be absolute
dataset/ETHPy150Open zalando/turnstile/turnstile/models/specifications.py/Specification.validate_uri