src/vs/workbench/contrib/extensions/browser/extensionsDependencyChecker.ts/ExtensionDependencyChecker/getAllMissingDependencies
class ExtensionDependencyChecker:	private async getAllMissingDependencies(): Promise<string[]> {
		await this.extensionService.whenInstalledExtensionsRegistered();
		const runningExtensionsIds: Set<string> = this.extensionService.extensions.reduce((result, r) => { result.add(r.identifier.value.toLowerCase()); return result; }, new Set<string>());
		const missingDependencies: Set<string> = new Set<string>();
		for (const extension of this.extensionService.extensions) {
			if (extension.extensionDependencies) {
				extension.extensionDependencies.forEach(dep => {
					if (!runningExtensionsIds.has(dep.toLowerCase())) {
						missingDependencies.add(dep);
					}
				});
			}
		}
		return [...missingDependencies.values()];
	}