var requestExecuter = _requestExecuters.GetOrAdd(databaseName,
	new RequestExecuter(Url, databaseName, ApiKey));

var requestExecuter = _requestExecuters.GetOrAdd(databaseName,
	ignored => new RequestExecuter(Url, databaseName, ApiKey)));

var requestExecuter = _requestExecuters.GetOrAdd(databaseName,
	dbName => new RequestExecuter(Url, dbName, ApiKey)));

var requestExecuter = _requestExecuters.GetOrAdd(databaseName,
	new Lazy<RequestExecuter>(()=> new RequestExecuter(Url, databaseName, ApiKey))).Value;

var requestExecuter = _requestExecuters.GetOrAdd(databaseName,
	dbName => new Lazy<RequestExecuter>(()=> new RequestExecuter(Url, dbName, ApiKey))).Value;