ensureInvisibility method

void ensureInvisibility ()

Turns off node visibility - if called node will NOT be shown in output regardless of whether it comes from import by reference or not

Implementation

void ensureInvisibility() {
  nodeVisible = false;

//2.5.3 20151120
// Node.prototype.ensureInvisibility = function () {
//     this.nodeVisible = false;
// };
}