src/vs/workbench/contrib/customEditor/browser/customEditors.ts/CustomEditorService/updateContexts
class CustomEditorService:	private updateContexts() {
		const activeEditorPane = this.editorService.activeEditorPane;
		const resource = activeEditorPane?.input?.resource;
		if (!resource) {
			this._activeCustomEditorId.reset();
			this._focusedCustomEditorIsEditable.reset();
			return;
		}

		this._activeCustomEditorId.set(activeEditorPane?.input instanceof CustomEditorInput ? activeEditorPane.input.viewType : '');
		this._focusedCustomEditorIsEditable.set(activeEditorPane?.input instanceof CustomEditorInput);
	}