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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 fill_zero( x=None, y=None, label=None, color=None, width=None, dash=None, opacity=None, mode='lines+markers', **kargs ):
 """Fill to zero. Parameters x : array-like, optional y : TODO, optional label : TODO, optional Returns ------- Chart """

    return line(
        x=x,
        y=y,
        label=label,
        color=color,
        width=width,
        dash=dash,
        opacity=opacity,
        mode=mode,
        fill='tozeroy',
        **kargs
    )