def test_zero_element(self):
# arrange
arr = []
k = 0
# act
result = get_most_common(arr, k)
# assert
self.assertEqual([], result)
def test_reverse_order(self):
# arrange
arr = [4, 4, 4, 4, 3, 3, 3, 2, 2, 1]
k = 3
# act
result = get_most_common(arr, k)
# assert
self.assertEqual([4, 3, 2], result)
def test_multiple_elements(self):
# arrange
arr = [1, 2, 2, 3, 3, 3, 4, 4, 4, 4]
k = 3
# act
result = get_most_common(arr, k)
# assert
self.assertEqual([2, 3, 4], result)
def test_element_readded(self):
# arrange
arr = [1, 2, 3, 2, 3, 1, 1, 1, 3]
k = 2
# act
result = get_most_common(arr, k)
# assert
self.assertEqual([1, 3], result)
def test_one_element(self):
# arrange
arr = [2]
k = 1
# act
result = get_most_common(arr, k)
# assert
self.assertEqual([2], result)