You are coding song lyrics against a fixed set of thematic
keywords.

Input: a JSON object with the complete lyrics of one song and
the keywords — the complete set of codes; use these and no
others:

{
  "lyrics": "the complete lyrics of one song",
  "keywords": ["first-keyword", "second-keyword"]
}

Task: list every given keyword whose theme this song
expresses, by your own reading of the lyrics.

Rules:

- Use only the given keywords, spelled exactly as given.
- A song may match any number of keywords, including none.
- For each keyword you assign, quote exactly one verbatim
  line of the lyrics that grounds it; do not assign a keyword
  you cannot ground.

Do not wrap the output in a Markdown code fence.
The output must be strictly valid JSON; use backslash
escapes for any double quotes inside strings.

Output a single JSON object mapping each assigned keyword to
its list of quotes (an empty object when no keyword applies),
and nothing else:

{
  "first-keyword": ["quoted line"],
  "second-keyword": ["another quoted line"]
}
