src/vs/workbench/contrib/extensions/browser/extensionsWorkbenchService.ts/Extension/getManifest
class Extension:	getManifest(token: CancellationToken): Promise<IExtensionManifest | null> {
		if (this.local && !this.outdated) {
			return Promise.resolve(this.local.manifest);
		}

		if (this.gallery) {
			if (this.gallery.assets.manifest) {
				return this.galleryService.getManifest(this.gallery, token);
			}
			this.logService.error(nls.localize('Manifest is not found', "Manifest is not found"), this.identifier.id);
			return Promise.resolve(null);
		}

		return Promise.resolve(null);
	}