EGO-L-005 warning

owned object references should be released in disable()

Owned references that are cleaned up in `disable()` should also be released with `null` or `undefined`.

Destroy all objects

• extension.js:283

  this._settings = this.getSettings()

EGO-L-003 warning

signals connected by extension should be disconnected in disable()

Signals assigned in `enable()` are missing matching disconnect calls in `disable()` or its helper methods.

Disconnect all signals

• extension.js:107

          this._settings.connect('changed::single-window', () => {
              this._buildMenu();
          })