def METHOD_NAME(typename: str) -> Optional[Type[Sequence]]:
    if typename in Sequence.registry:
        seq_types = Sequence.registry.get(typename)
        if len(seq_types) > 1:
            raise ValueError(f'Multiple matching sequence types for type name \'{typename}\'. '
                             f'Please include sequence package name.')
        return seq_types[0]
    else:
        return None