def full_name(cla55: Optional[type]) -> str:
    """
    Return the full name (including module) of the given class.
    """
    # Special case to handle None:
    if cla55 is None:
        return "?"

    if issubclass(cla55, Initializer) and cla55 not in [Initializer, PretrainedModelInitializer]:
        init_fn = cla55()._init_function
        return f"{init_fn.__module__}.{init_fn.__name__}"

    origin = getattr(cla55, '__origin__', None)
    args = getattr(cla55, '__args__', ())

    # Special handling for compound types
    if origin in (Dict, dict):
        key_type, value_type = args
        return f"""Dict[{full_name(key_type)}, {full_name(value_type)}]"""
    elif origin in (Tuple, tuple, List, list, Sequence, collections.abc.Sequence):
        return f"""{_remove_prefix(str(origin))}[{", ".join(full_name(arg) for arg in args)}]"""
    elif origin == Union:
        # Special special case to handle optional types:
        if len(args) == 2 and args[-1] == type(None):
            return f"""Optional[{full_name(args[0])}]"""
        else:
            return f"""Union[{", ".join(full_name(arg) for arg in args)}]"""
    else:
        return _remove_prefix(f"{cla55.__module__}.{cla55.__name__}")