But how many developers understand how HashMap works internally? A few days ago, I read a lot of the source code for ...

If a constraint involves a negated boolean variable, assigning a boolean numpy array results in an error when calling Constraint.violation. Assigning a list works ...

I've created the code for all of the endpoints for Employee and Departments but just returning the basic objects not using ResponseEntities. In the Exercise you should be returning ResponseEntities ...