text: import pytest
  
  from calculator.calc import check_power_of_2
  
  def test_positive_case():
      """Testing that actual powers of 2 give True"""
      assert check_power_of_2(65536)
      
  def test_negative_case():
      """Testing that non-powers of 2 give False"""
      assert not check_power_of_2(12)    
  