Answer Key and Calibration

For é, Python length is 1 code point and UTF-8 length is 2 bytes. The quoted CSV record has two fields, with topic A,B. Header-only data is valid empty history; a blank data record is rejected by this lab. Three identical 10-minute sessions give count 3 and total 30. A digest covers raw bytes, so equivalent line endings may produce different digests.

For transfer, records X/10, X/10 and Y/20 give overall count 3, total 40, X count 2/total 20 and Y count 1/total 20. Empty history has count/total zero and an empty topic map. One plausible result schema uses nested objects per topic; different explicit representations are acceptable. A copied result without an independent implementation and reasoning does not establish transfer.

A fault control should be discriminating: identical rows catch deduplication; one valid row followed by an invalid row catches partial-success reporting. Changing expected answers to match the bug fails the evidence requirement.