src/vs/platform/extensionManagement/node/extensionManagementService.ts/ExtensionManagementService/extractAndInstall
class ExtensionManagementService:	private async extractAndInstall({ zipPath, identifierWithVersion, metadata }: InstallableExtension, token: CancellationToken): Promise<ILocalExtension> {
		let local = await this.extensionsScanner.extractUserExtension(identifierWithVersion, zipPath, token);
		this.logService.info('Installation completed.', identifierWithVersion.id);
		if (metadata) {
			local = await this.extensionsScanner.saveMetadataForLocalExtension(local, metadata);
		}
		return local;
	}