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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 set_ax_spines(ax=None, *, c="k", lw=3, zorder=10):
 """Easily set the properties of all four axis spines. Parameters ax : matplotlib AxesSubplot object (optional) Axis to set. If None, uses current axis. Default is None. c : any matplotlib color argument (optional) Spine color. Default is k. lw : number (optional) Spine linewidth. Default is 3. zorder : number (optional) Spine zorder. Default is 10. """

    # get ax
    if ax is None:
        ax = plt.gca()
    # apply
    for key in ["bottom", "top", "right", "left"]:
        ax.spines[key].set_color(c)
        ax.spines[key].set_linewidth(lw)
        ax.spines[key].zorder = zorder