Get some strokes of pointlist

    Parameters
    ----------
    pointlist : list of lists of dicts
    strokes : list of integers

    Returns
    -------
    list of lists of dicts

def _get_part(pointlist, strokes):
    """Get some strokes of pointlist

    Parameters
    ----------
    pointlist : list of lists of dicts
    strokes : list of integers

    Returns
    -------
    list of lists of dicts
    """
    result = []
    strokes = sorted(strokes)
    for stroke_index in strokes:
        result.append(pointlist[stroke_index])
    return result