I'm not quite happy with the naming. I don't think the _ in front is necessary and I'm also not quite sure if the name is very intuitiv. It's completely unclear from the name, when and why this is ```False``` by default. ```show(open=false)```, looks very weird. I'd like the name to convey some meaning about why this is being set, If I understand it correctly this is only set when the window is opened the first time? Maybe we can call the variable ```firstOpen``` or ```newWindow``` or something similar?