I have implemented the required code for “two_layer_model” in the Exercise 1, When the cell below the function is called, I get the following error:

```
Error: Wrong output for variable W1.
Error: Wrong output for variable b1.
Error: Wrong output for variable W2.
Error: Wrong output for variable b2.
3 Tests passed
1 Tests failed
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-48-f9ec5304d38d> in <module>
3 print("Cost after first iteration: " + str(costs[0]))
4
----> 5 two_layer_model_test(two_layer_model)
~/work/release/W4A2/public_tests.py in two_layer_model_test(target)
75 ]
76
---> 77 multiple_test(test_cases, target)
78
79
~/work/release/W4A2/test_utils.py in multiple_test(test_cases, target)
140 print('\033[92m', success," Tests passed")
141 print('\033[91m', len(test_cases) - success, " Tests failed")
--> 142 raise AssertionError("Not all tests were passed for {}. Check your equations and avoid using global variables inside the function.".format(target.__name__))
143
AssertionError: Not all tests were passed for two_layer_model. Check your equations and avoid using global variables inside the function.
```

However cost of iteration are exactly what they are supposed to be:

Cost after iteration 1: 0.6926114346158595

Cost after first iteration: 0.693049735659989

Cost after iteration 1: 0.6915746967050506

Cost after iteration 1: 0.6915746967050506

Cost after iteration 1: 0.6915746967050506

Cost after iteration 2: 0.6899956541494738

Furthermore when this model is run on the training data and predict data for the images I get the exactly the same accuracy and cost as in the output.

Cost after iteration 0: 0.693049735659989

Cost after iteration 100: 0.6464320953428849

Cost after iteration 200: 0.6325140647912677

Cost after iteration 300: 0.6015024920354665

Cost after iteration 400: 0.5601966311605747

Cost after iteration 500: 0.5158304772764729

Cost after iteration 600: 0.4754901313943325

Cost after iteration 700: 0.43391631512257495

Cost after iteration 800: 0.4007977536203886

Cost after iteration 900: 0.3580705011323798

Cost after iteration 1000: 0.3394281538366413

Cost after iteration 1100: 0.30527536361962654

Cost after iteration 1200: 0.2749137728213015

Cost after iteration 1300: 0.2468176821061484

Cost after iteration 1400: 0.19850735037466102

Cost after iteration 1500: 0.17448318112556638

Cost after iteration 1600: 0.1708076297809692

Cost after iteration 1700: 0.11306524562164715

Cost after iteration 1800: 0.09629426845937156

Cost after iteration 1900: 0.0834261795972687

Cost after iteration 2000: 0.07439078704319085

Cost after iteration 2100: 0.06630748132267933

Cost after iteration 2200: 0.05919329501038172

Cost after iteration 2300: 0.053361403485605606

Cost after iteration 2400: 0.04855478562877019

Cost after iteration 2499: 0.04421498215868956

If the model is working fine on the training and test data and giving the same results as mentioned in the “Expected Output” then Why am I getting the error when two_layer_model_test(two_layer_model) is executed.