def subsample(rows):
    """Extract 3 rows from rows for testing purposes.
    The first, last and middlish value are extracted.

    Args:
        rows (list): Data to be subsetted.
    Returns:
        _rows (list): 3 points sampled from the input.
    """
    n = len(rows)
    if n > 3:
        rows = [rows[0], rows[-1], rows[int((n+1)/2)]]
    return rows