def METHOD_NAME(ax, start, stop, y_offs = 0, height=1.5, label=None, labelHeight=None,
             vlines=True, color='k', arrowstyle='<|-|>', **plot_kws):
    '''
    Draw an arrow to indicate an interval.
    '''
    if labelHeight is None:
        labelHeight = height + 0.2
    arrow = matplotlib.patches.FancyArrowPatch(
        posA=(start, height+y_offs), posB=(stop, height+y_offs), arrowstyle=arrowstyle,
        color=color, mutation_scale=7, **plot_kws)
    ax.add_patch(arrow)
    if vlines:
        ax.plot([start, start], [0+y_offs, height+y_offs], '--', color=color, **plot_kws)
        ax.plot([stop, stop], [0+y_offs, height+y_offs], '--', color=color, **plot_kws)
    if label is not None:
        ax.text((start + stop) / 2, labelHeight+y_offs, label, color=color,
                horizontalalignment='center')