import collections

import datetime

import decimal

import functools

from beancount.core import account as bc_account

from beancount.core import amount as bc_amount

from beancount.core import convert as bc_convert

from typing import (

    cast,

    Callable,

    Hashable,

    Iterable,

    Iterator,

    MutableMapping,

    * The `units` field is our Amount object (which simply declares that the

      number is always a Decimal—see that docstring for details)

    * The `meta` field is a PostingMeta object

    """

    __slots__ = ()

    account: Account

    units: Amount

    # mypy correctly complains that our MutableMapping is not compatible

    # with Beancount's meta type declaration of Optional[Dict]. IMO

    # Beancount's type declaration is a smidge too specific: I think its type

    # declaration should also use MutableMapping, because it would be very

    # unusual for code to specifically require a Dict over that.

    # If it did, this declaration would pass without issue.

    meta: PostingMeta  # type:ignore[assignment]