src/vs/editor/contrib/anchorSelect/anchorSelect.ts/SelectionAnchorController/cancelSelectionAnchor
class SelectionAnchorController:	cancelSelectionAnchor(): void {
		if (this.decorationId) {
			this.editor.deltaDecorations([this.decorationId], []);
			this.decorationId = undefined;
			this.selectionAnchorSetContextKey.set(false);
		}
	}