`the problem with state` snippet output

[VitGottwald]

First of all thank you for this wonderful book! I bought it after having read about half of it on learnpub. It is the best javascript book I found so far!

Under the subsection the problem with state of Stateful Method Decorators section, the code

musician.fullName() //=> Raymond Smullyan

is incorrect - the statement actually returns TypeError: Cannot read property 'fullName' of undefined. This is because once being called for the 2nd time returns undefined and hence musician is undefined.