Persistent storage in IntelliJ plugin

I am developing an IntelliJ plugin, and I would like to store some settings information as a string. How am I able to store it? I found that PersistentStateComponent<T> is for this purpose, but I didn't find any working and simple use of this class.

Could you please provide some info , how am I able to create a class with only one String argument and methods like:

     Void Save(String value)
    {
       //save SettingsAsString
    {

     String Load()
    {
       //Do something
       return savedSettingsAsString
    }

Thank You!