def METHOD_NAME(data_key: str, band: tuple):
    ctx = get_context()
    assert band == ctx.band
    meta = ctx.get_chunks_meta([data_key], fields=["bands"])[0]
    assert len(meta) == 1
    ctx.get_chunks_result([data_key], fetch_only=True)
    # fetched, two bands have the data
    meta = ctx.get_chunks_meta([data_key], fields=["bands"])[0]
    assert len(meta["bands"]) == 2