"""Complete one function per focused Builder lesson. No network or paid calls."""

def parse_request(value):
    # Lesson 02: exactly one non-empty string field: id.
    raise NotImplementedError("Implement the request contract")

def validate_answer(envelope, source):
    # Lesson 03: status ok; exactly id/time; non-empty strings; source agreement.
    raise NotImplementedError("Validate status, shape and evidence")

def lookup(caller, request, records):
    # Lesson 04: validate; guest may read public only; return explicit status.
    raise NotImplementedError("Enforce the trusted record scope")

def once(operation_id, operation, cache):
    # Lesson 05: reuse before calling. This cache is intentionally in-memory.
    raise NotImplementedError("Avoid a repeated side effect")

def run(caller, request, records, operation_id, cache):
    # Lesson 06: compose parser/lookup/validator/once. Reauthorize before reuse;
    # bind identity to caller, request and source; changed intent -> key_conflict.
    raise NotImplementedError("Integrate the bounded offline workflow")