如何添加对函数的调用？

total_pay是父类Employee的方法，SalariedEmployee和HourlyEmployee是其子类。

我知道我想做什么，我只是不知道怎么做。我想在之前的pay方法调用中添加所有付款变量。我如何访问以前的电话？更具体地说，付费方式中的付款对象。

class Employee:

"""An employee of a company.
This is an abstract class. Only child classes should be instantiated.

=== Public attributes ===
id_: This employee's ID number.
name: This employee's name.
"""
id_: int
name: str

def __init__(self, id_: int, name: str) -> None:
    """Initialize this employee.

    Note: This initializer is meant for internal use only;
    Employee is an abstract class and should not be instantiated directly.
    """
    self.id_ = id_
    self.name = name
    self.counter = 0

def get_monthly_payment(self) -> float:
    """Return the amount that this Employee should be paid in one month.

    Round the amount to the nearest cent.
    """
    raise NotImplementedError

def pay(self, pay_date: date) -> None:
    """Pay this Employee on the given date and record the payment.

    (Assume this is called once per month.)
    """
    payment = self.get_monthly_payment()
    print(f'An employee was paid {payment} on {pay_date}.')

def total_pay(self) -> float:
    """Return the total amount of pay this Employee has received.

    >>> e = SalariedEmployee(14, 'Gilbert the cat', 1200.0)
    >>> e.pay(date(2018, 6, 28))
    An employee was paid 100.0 on 2018-06-28.
    >>> e.pay(date(2018, 7, 28))
    An employee was paid 100.0 on 2018-07-28.
    >>> e.pay(date(2018, 8, 28))
    An employee was paid 100.0 on 2018-08-28.
    >>> e.total_pay()
    300.0
    """

在多次调用pay方法之后，total_pay方法应该返回所有这些值的总和。可以假设付费方式每月只调用一次。