language :Java

please don't use import, or any classes that you defined before, I just set up my environment and all the codes that exist here on Chegg that answers the same question is not working

please provide the implementation of all the methods

Write a method max() that takes a reference to the first node in a linked list as argument and returns the value of the maximum key in the list. Assume that all keys are positive integers, and return 0 if the list is empty.