The GetPersistentVal method retrieves a value previously saved to the persistent storage with the SetPersistentVal method.
GetPersistentVal(key)
Required. String that specifies the name of the value. The string may only contain upper and lower-case A-Z, the numeric characters, 0-9, underscore, dot and colon. Length of the string is limited to 255 characters. Value names are not case sensitive.
Returns the value loaded from the persistent storage. If a value with the specified name was not found, the return value is null.