Issue in theAdaptive authentication using function library sample

[sahandilshan]

Description:
Adaptive authentication using function library provide a sample where it check the age of the user. According to the age_based functional library, it only has the getAge() function. But in the authentication script, it says it has two functions (getAge and validateDOB)
https://is.docs.wso2.com/en/latest/guides/adaptive-auth/adaptive-auth-with-function-lib-sample/

An exception throws when using the given authentication script. Either we have to update the authentication script or update the functional library.