from abc import ABC, abstractmethod
from typing import Optional, Callable, Union


class IterableABC(ABC, list):

    @abstractmethod
    def __init__(self):
        list.__init__(self)

    @abstractmethod
    def any(self, func: Callable) -> bool: pass

    @abstractmethod
    def all(self, func: Callable) -> bool: pass

    @abstractmethod
    def average(self, t: type, func: Callable) -> Union[int, float, complex]: pass

    @abstractmethod
    def contains(self, value: object) -> bool: pass

    @abstractmethod
    def count(self, func: Callable) -> int: pass

    @abstractmethod
    def distinct(self, func: Callable) -> 'IterableABC': pass

    @abstractmethod
    def element_at(self, index: int) -> any: pass

    @abstractmethod
    def element_at_or_default(self, index: int) -> Optional[any]: pass

    @abstractmethod
    def last(self) -> any: pass

    @abstractmethod
    def last_or_default(self) -> any: pass

    @abstractmethod
    def first(self) -> any: pass

    @abstractmethod
    def first_or_default(self) -> any: pass

    @abstractmethod
    def for_each(self, func: Callable): pass

    @abstractmethod
    def order_by(self, func: Callable) -> 'IterableABC': pass

    @abstractmethod
    def order_by_descending(self, func: Callable) -> 'IterableABC': pass

    @abstractmethod
    def single(self) -> any: pass

    @abstractmethod
    def single_or_default(self) -> Optional[any]: pass

    @abstractmethod
    def where(self, func: Callable) -> 'IterableABC': pass