A developer wrote a class named asccuntRisteryManager that relies on field history tracking.

Create Accountdistory records manually in the test setup and write a query to get them.

Use @isTest (SeeAllData=true] to see historical data from the org and query for Accountdistory records.

Use Test. isRunningTest (] in getAccountHistory() to conditionally return fake AccountHistory records.

The tact method should he delated since this code cannat be tested