src/vs/workbench/services/keybinding/browser/keybindingService.ts/WorkbenchKeybindingService/_handleKeybinding
class WorkbenchKeybindingService:	private _handleKeybinding(extensionId: ExtensionIdentifier, isBuiltin: boolean, idx: number, keybindings: ContributedKeyBinding, collector: ExtensionMessageCollector, result: IExtensionKeybindingRule[]): void {

		const rejects: string[] = [];

		if (isValidContributedKeyBinding(keybindings, rejects)) {
			const rule = this._asCommandRule(extensionId, isBuiltin, idx++, keybindings);
			if (rule) {
				result.push(rule);
			}
		}

		if (rejects.length > 0) {
			collector.error(nls.localize(
				'invalid.keybindings',
				"Invalid `contributes.{0}`: {1}",
				keybindingsExtPoint.name,
				rejects.join('\n')
			));
		}
	}