Bugfix

The model receives the prompt (and optional system message). The run uses scorer contains_all with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Fix the bug and return corrected Python code only.\n\ndef tail(items):\n    return items[1:]\n

{
  "expected_contains": [
    "items[-1]",
    "if not items",
    "return None"
  ]
}