class Calculator:
    def sum(self, a, b):
        return a + b

from unittest import TestCase
from main import Calculator

class TestCalculator(TestCase):
    def setUp(self):
        self.calc = Calculator()

    def test_sum(self):
        answer = self.calc.sum(2, 4)
        self.assertEqual(answer, 6)

import time

class Calculator:
    def sum(self, a, b):
        time.sleep(10)
        return a + b

from unittest import TestCase
from unittest.mock import patch

class TestCalculator(TestCase):
    @patch('main.Calculator.sum', return_value=9)
    def test_sum(self, sum):
        self.assertEqual(sum(2,3), 9)

import requests

class Blog:
    def __init__(self, name):
        self.name = name

    def posts(self):
        response = requests.get("https://jsonplaceholder.typicode.com/posts")

        return response.json()

    def __repr__(self):
        return '<Blog: {}>'.format(self.name)

from unittest import TestCase
from unittest.mock import patch, Mock


class TestBlog(TestCase):
    @patch('main.Blog')
    def test_blog_posts(self):
        blog = Mock()

        blog.posts.return_value = [
            {
                'userId': 1,
                'id': 1,
                'title': 'Test Title',
                'body': 'Body content'
            }
        ]

        response = blog.posts()
        self.assertIsNotNone(response)
        self.assertIsInstance(response[0], dict)