"""Exercise 10.8.4 — Closing the quotes

Chapter 10: Functions — Everyday Programming

This function should have a one-line docstring and return a perimeter.

This program contains exactly one bug. Solution: sol_10_8_4.py
"""

def square_perimeter(side):
    """Return the perimeter of a square.
    return side * 4

print(square_perimeter(3))  # 12