src/vs/workbench/services/keybinding/common/keybindingEditing.ts/KeybindingsEditingService/removeUnassignedDefaultKeybinding
class KeybindingsEditingService:	private removeUnassignedDefaultKeybinding(keybindingItem: ResolvedKeybindingItem, model: ITextModel): void {
		const { tabSize, insertSpaces } = model.getOptions();
		const eol = model.getEOL();
		const userKeybindingEntries = <IUserFriendlyKeybinding[]>json.parse(model.getValue());
		const indices = this.findUnassignedDefaultKeybindingEntryIndex(keybindingItem, userKeybindingEntries).reverse();
		for (const index of indices) {
			this.applyEditsToBuffer(setProperty(model.getValue(), [index], undefined, { tabSize, insertSpaces, eol })[0], model);
		}
	}