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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def draw_annotation(img, boxes, klass, is_crowd=None):
 """Will not modify img"""

    labels = []
    assert len(boxes) == len(klass)
    if is_crowd is not None:
        assert len(boxes) == len(is_crowd)
        for cls, crd in zip(klass, is_crowd):
            clsname = cfg.DATA.CLASS_NAMES[cls]
            if crd == 1:
                clsname += ';Crowd'
            labels.append(clsname)
    else:
        for cls in klass:
            labels.append(cfg.DATA.CLASS_NAMES[cls])
    img = viz.draw_boxes(img, boxes, labels)
    return img