def leapYear(year: int = 2020)-> None:
    """
    This function tests and `prints` whether a given year is a `Leap year` or not. Returns `None` if bound to a variable.

    Args: This function takes exactly one argument.

    `year: int` : The literal of this argument should be of `integer (int)` data type.
    """
    
    if year % 4 == 0:
        if year%100 == 0:
            if year %400 == 0:
                print(f"{year} is a leap year")
            else:
                print(f"{year} is not a leap year")
        else:
            print(f"{year} is a leap year")
    else:
        print(f"{year} is not a leap year")

    return None