Assertion Error in Q11

I have tried everything(like- starting the assignment from the beginning, running all the cells again, tried running it on collab too) but I am not able to pass the exam due to this error.
The question was -
Q11: Create a dataframe with 10 countires that have highest number of tests per million people.
My solution -
highest_tests_df = combined_df.sort_values(“tests_per_million”,ascending=False).head(10)

Here is the kink of my notebook

Please help me in passing the exam

@aakashns NEED HELP IN THIS CASE
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@abhirajshourya
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