# Deliberately unfinished learner scaffold. Keep separate from worked_lab.py.
from pathlib import Path

def load_and_validate(source):
    raise NotImplementedError('Implement this module’s source/partition contract')

def perform_task(validated):
    raise NotImplementedError('Implement the explained query/model/analysis')

def check_and_explain(result):
    raise NotImplementedError('Check grain/baseline/errors and document limitations')

if __name__=='__main__':
    raise SystemExit('Complete the functions and tests before running your own workflow.')