def astuple(
    inst,
    recurse=True,
    filter=None,
    tuple_factory=tuple,
    retain_collection_types=False,
):
    """
    Return the *attrs* attribute values of *inst* as a tuple.

    Optionally recurse into other *attrs*-decorated classes.

    :param inst: Instance of an *attrs*-decorated class.
    :param bool recurse: Recurse into classes that are also
        *attrs*-decorated.
    :param callable filter: A callable whose return code determines whether an
        attribute or element is included (``True``) or dropped (``False``).  Is
        called with the `attrs.Attribute` as the first argument and the
        value as the second argument.
    :param callable tuple_factory: A callable to produce tuples from.  For
        example, to produce lists instead of tuples.
    :param bool retain_collection_types: Do not convert to ``list``
        or ``dict`` when encountering an attribute which type is
        ``tuple``, ``dict`` or ``set``.  Only meaningful if ``recurse`` is
        ``True``.

    :rtype: return type of *tuple_factory*

    :raise attrs.exceptions.NotAnAttrsClassError: If *cls* is not an *attrs*
        class.

    ..  versionadded:: 16.2.0
    """
    attrs = fields(inst.__class__)
    rv = []
    retain = retain_collection_types  # Very long. :/
    for a in attrs:
        v = getattr(inst, a.name)
        if filter is not None and not filter(a, v):
            continue
        if recurse is True:
            if has(v.__class__):
                rv.append(
                    astuple(
                        v,
                        recurse=True,
                        filter=filter,
                        tuple_factory=tuple_factory,
                        retain_collection_types=retain,
                    )
                )
            elif isinstance(v, (tuple, list, set, frozenset)):
                cf = v.__class__ if retain is True else list
                rv.append(
                    cf(
                        [
                            astuple(
                                j,
                                recurse=True,
                                filter=filter,
                                tuple_factory=tuple_factory,
                                retain_collection_types=retain,
                            )
                            if has(j.__class__)
                            else j
                            for j in v
                        ]
                    )
                )
            elif isinstance(v, dict):
                df = v.__class__ if retain is True else dict
                rv.append(
                    df(
                        (
                            astuple(
                                kk,
                                tuple_factory=tuple_factory,
                                retain_collection_types=retain,
                            )
                            if has(kk.__class__)
                            else kk,
                            astuple(
                                vv,
                                tuple_factory=tuple_factory,
                                retain_collection_types=retain,
                            )
                            if has(vv.__class__)
                            else vv,
                        )
                        for kk, vv in v.items()
                    )
                )
            else:
                rv.append(v)
        else:
            rv.append(v)

    return rv if tuple_factory is list else tuple_factory(rv)

    Return the *attrs* attribute values of *inst* as a tuple.

    Optionally recurse into other *attrs*-decorated classes.

    :param inst: Instance of an *attrs*-decorated class.
    :param bool recurse: Recurse into classes that are also
        *attrs*-decorated.
    :param callable filter: A callable whose return code determines whether an
        attribute or element is included (``True``) or dropped (``False``).  Is
        called with the `attrs.Attribute` as the first argument and the
        value as the second argument.
    :param callable tuple_factory: A callable to produce tuples from.  For
        example, to produce lists instead of tuples.
    :param bool retain_collection_types: Do not convert to ``list``
        or ``dict`` when encountering an attribute which type is
        ``tuple``, ``dict`` or ``set``.  Only meaningful if ``recurse`` is
        ``True``.

    :rtype: return type of *tuple_factory*

    :raise attrs.exceptions.NotAnAttrsClassError: If *cls* is not an *attrs*
        class.

    ..  versionadded:: 16.2.0
    
product/gradle-plugin/src/main/python/attr/_funcs.py