in src/connector.ts [111:124]
private cacheKey(opts: ConnectionOptions): string {
//TODO: for now, the cache key function must be synchronous.
// When we implement the async connection info from
// https://github.com/GoogleCloudPlatform/cloud-sql-nodejs-connector/pull/426
// then the cache key should contain both the domain name
// and the resolved instance name.
return (
(opts.instanceConnectionName || opts.domainName) +
'-' +
opts.authType +
'-' +
opts.ipType
);
}