Hi Chris,
"disappear» = hide or delete?
It seems you wanted a load and unload button.
Samples can be downloaded here: edge commons - copie.zip - Box
You can replace:sym.$("button").off().on("click", function(){ newStage.deleteSymbol(); }); // delete
by:sym.$("button").off().on("click", function(){ newStage.getSymbolElement().hide(); }); // hide