How to use the fava.core.budgets.calculate_budget function in fava

def test_budgets_daily(budgets_doc):
    """
    2016-05-01 custom "budget" Expenses:Books "daily" 2.5 EUR"""

    assert "EUR" not in calculate_budget(
        budgets_doc, "Expenses:Books", date(2010, 2, 1), date(2010, 2, 2)
    )
    assert calculate_budget(
        budgets_doc, "Expenses:Books", date(2016, 5, 1), date(2016, 5, 2)
    )["EUR"] == D("2.5")
    assert calculate_budget(
        budgets_doc, "Expenses:Books", date(2016, 5, 1), date(2016, 5, 3)
    )["EUR"] == D("5.0")
    assert calculate_budget(
        budgets_doc, "Expenses:Books", date(2016, 9, 2), date(2016, 9, 3)
    )["EUR"] == D("2.5")
    assert calculate_budget(
        budgets_doc, "Expenses:Books", date(2018, 12, 31), date(2019, 1, 1)
    )["EUR"] == D("2.5")

def test_budgets(load_doc):
    """
    2016-01-01 custom "budget" Expenses:Groceries "weekly" 100.00 CNY
    2016-06-01 custom "budget" Expenses:Groceries "weekly"  10.00 EUR
    2016-06-01 custom "budget" Expenses:Groceries "asdfasdf"  10.00 EUR
    2016-06-01 custom "budget" Expenses:Groceries 10.00 EUR
    """
    entries, _, _ = load_doc
    budgets, errors = parse_budgets(entries)

    assert len(errors) == 2

    assert (
        calculate_budget(
            budgets, "Expenses", date(2016, 6, 1), date(2016, 6, 8)
        )
        == {}
    )

    budgets = calculate_budget(
        budgets, "Expenses:Groceries", date(2016, 6, 1), date(2016, 6, 8)
    )

    assert budgets["CNY"] == D("100")
    assert budgets["EUR"] == D("10")

def test_budgets_monthly(budgets_doc):
    """
    2014-05-01 custom "budget" Expenses:Books "monthly" 100 EUR"""

    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2016, 1, 1), date(2016, 1, 2)
        )["EUR"]
        == D("100") / 31
    )
    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2016, 2, 1), date(2016, 2, 2)
        )["EUR"]
        == D("100") / 29
    )
    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2018, 3, 31), date(2018, 4, 1)
        )["EUR"]
        == D("100") / 31
    )

def test_budgets_doc_yearly(budgets_doc):
    """
    2010-01-01 custom "budget" Expenses:Books "yearly" 99999.87 EUR"""

    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2011, 2, 1), date(2011, 2, 2)
        )["EUR"]
        == D("99999.87") / 365
    )

def test_budgets_weekly(budgets_doc):
    """
    2016-05-01 custom "budget" Expenses:Books "weekly" 21 EUR"""

    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2016, 5, 1), date(2016, 5, 2)
        )["EUR"]
        == D("21") / 7
    )
    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2016, 9, 1), date(2016, 9, 2)
        )["EUR"]
        == D("21") / 7
    )

2016-06-01 custom "budget" Expenses:Groceries "asdfasdf"  10.00 EUR
    2016-06-01 custom "budget" Expenses:Groceries 10.00 EUR
    """
    entries, _, _ = load_doc
    budgets, errors = parse_budgets(entries)

    assert len(errors) == 2

    assert (
        calculate_budget(
            budgets, "Expenses", date(2016, 6, 1), date(2016, 6, 8)
        )
        == {}
    )

    budgets = calculate_budget(
        budgets, "Expenses:Groceries", date(2016, 6, 1), date(2016, 6, 8)
    )

    assert budgets["CNY"] == D("100")
    assert budgets["EUR"] == D("10")

def test_budgets_doc_quarterly(budgets_doc):
    """
    2014-05-01 custom "budget" Expenses:Books "quarterly" 123456.7 EUR"""

    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2016, 2, 1), date(2016, 2, 2)
        )["EUR"]
        == D("123456.7") / 91
    )
    assert (
        calculate_budget(
            budgets_doc, "Expenses:Books", date(2016, 8, 15), date(2016, 8, 16)
        )["EUR"]
        == D("123456.7") / 92
    )