I don't know Mint but want to give a data point about that. The `=` is rebinding, what that mean is the original value doesn't change. If you pass that counter

I don't know Mint but want to give a data point about that. The `=` is rebinding, what that mean is the original value doesn't change. If you pass that counter variable somewhere, it has its original value. the `count = counter + 1` here mean that a new memory block is allocated, get a value, and the `counter` in this scope is point to it. The old value in the original memory block won't change. At least, that's the case of Erlang/Elixir.