Yes, absolutely. Mutable HashMaps are by default not thread-safe, and using them in this manner can result in undefined behaviour. Missing entries is actually a fairly benign manifestation.
Depending on the underlying implementation, it also possible to corrupt the HashMap data structure to the point where your program goes into an infinite loop.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.