src/vs/workbench/contrib/preferences/browser/keybindingsEditor.ts/KeybindingsEditor/getNewIndexOfUnassignedKeybinding
class KeybindingsEditor:	private getNewIndexOfUnassignedKeybinding(unassignedKeybinding: IKeybindingItemEntry): number {
		for (let index = 0; index < this.tableEntries.length; index++) {
			const entry = this.tableEntries[index];
			if (entry.templateId === KEYBINDING_ENTRY_TEMPLATE_ID) {
				const keybindingItemEntry = (<IKeybindingItemEntry>entry);
				if (keybindingItemEntry.keybindingItem.command === unassignedKeybinding.keybindingItem.command) {
					return index;
				}
			}
		}
		return -1;
	}