src/vs/workbench/services/extensions/common/extensionHostManager.ts/ExtensionHostManager/getCanonicalURI
class ExtensionHostManager:	public async getCanonicalURI(remoteAuthority: string, uri: URI): Promise<URI> {
		const proxy = await this._getProxy();
		if (!proxy) {
			throw new Error(`Cannot resolve canonical URI`);
		}
		const result = await proxy.$getCanonicalURI(remoteAuthority, uri);
		return URI.revive(result);
	}