src/vs/platform/environment/common/environmentService.ts/AbstractNativeEnvironmentService/extensionDevelopmentLocationURI
class AbstractNativeEnvironmentService:	get extensionDevelopmentLocationURI(): URI[] | undefined {
		const extensionDevelopmentPaths = this.args.extensionDevelopmentPath;
		if (Array.isArray(extensionDevelopmentPaths)) {
			return extensionDevelopmentPaths.map(extensionDevelopmentPath => {
				if (/^[^:/?#]+?:\/\//.test(extensionDevelopmentPath)) {
					return URI.parse(extensionDevelopmentPath);
				}

				return URI.file(normalize(extensionDevelopmentPath));
			});
		}

		return undefined;
	}