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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 rectangle_props(event):
 """ Returns the width, height, left, and bottom of a rectangle artist. Parameters event : PickEvent The pick event to process Returns -------- A dict with keys: `width` : The width of the rectangle `height` : The height of the rectangle `left` : The minimum x-coordinate of the rectangle `right` : The maximum x-coordinate of the rectangle `bottom` : The minimum y-coordinate of the rectangle `top` : The maximum y-coordinate of the rectangle `xcenter` : The mean x-coordinate of the rectangle `ycenter` : The mean y-coordinate of the rectangle `label` : The label for the rectangle or None """

    artist = event.artist
    width, height = artist.get_width(), artist.get_height()
    left, bottom = artist.xy
    right, top = left + width, bottom + height
    xcenter = left + 0.5 * width
    ycenter = bottom + 0.5 * height

    label = artist.get_label()
    if label is None or label.startswith('_nolegend'):
        try:
            label = artist._mpldatacursor_label
        except AttributeError:
            label = None

    return dict(width=width, height=height, left=left, bottom=bottom,
                label=label, right=right, top=top,
                xcenter=xcenter, ycenter=ycenter)