How does getByName() modify shared resources?

https://stackoverflow.com/questions/18542037/how-to-prove-that-hashmap-in-java-is-not-thread-safe Doing a little research I have found this post. It is basically saying that a HashMap is an array of buckets, with the keys being for the array and the values being the buckets. When you are adding/removing items to/from the Map, the internal array containing these buckets is automatically resized as needed. Errors would occur if a 'get' was called on the Map while this is occurring.