- if (isCalled) {
- if (options.throw === true) {
- throw new Error(`Function \`${functionName}\` can only be called once`);
- }
-
- return ret;
+ if (callCount === 1) {
+ returnValue = function_.apply(this, arguments_);
+ function_ = null;
+ } else if (options.throw === true) {
+ throw new Error(`Function \`${functionName}\` can only be called once`);