is_zero = eq_zero

    def ge_zero(self) -> bool:

        """Returns true if all amounts in the balance >= 0."""

        return self._all_amounts(operator.ge, 0)

    def le_zero(self) -> bool:

        """Returns true if all amounts in the balance <= 0."""

        return self._all_amounts(operator.le, 0)

    def format(self,

               sep: str=', ',

               empty: str="Zero balance",

    ) -> str:

        """Formats the balance as a string with the given parameters

        If the balance is zero, returns ``empty``. Otherwise, returns a string

        with each amount in the balance formatted as ``fmt``, separated by

        ``sep``.

        """

        amounts = [amount for amount in self.values() if amount.number]

        if not amounts:

            return empty

        amounts.sort(key=lambda amt: abs(amt.number), reverse=True)

        return sep.join(

            babel.numbers.format_currency(amt.number, amt.currency, fmt)

            for amt in amounts

        )

class MutableBalance(Balance):

#

# You should have received a copy of the GNU Affero General Public License

# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import itertools

from decimal import Decimal

import pytest

from . import testutil

from conservancy_beancount.reports import core

DEFAULT_STRINGS = [

    ({}, "Zero balance"),

    ({'JPY': 0, 'BRL': 0}, "Zero balance"),

    ({'USD': '20.00'}, "20.00 USD"),

    ({'EUR': '50.00', 'GBP': '80.00'}, "80.00 GBP, 50.00 EUR"),

    ({'JPY': '-5500.00', 'BRL': '-8500.00'}, "-8,500.00 BRL, -5,500 JPY"),

]

def test_empty_balance():

    balance = core.Balance()

@pytest.mark.parametrize('sep', [

    '; ',

    '—',

    '\0',

])

def test_format_sep(sep):

    bal_kwargs, expected = DEFAULT_STRINGS[-1]

    expected = expected.replace(', ', sep)

    amounts = testutil.balance_map(**bal_kwargs)

    balance = core.Balance(amounts)

    assert balance.format(sep=sep) == expected

@pytest.mark.parametrize('empty', [

    "N/A",

    "Zero",

    "ø",

])

def test_format_empty(empty):

    balance = core.Balance()

    assert balance.format(empty=empty) == empty