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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 adjustPlot(self, readsAx):
 """ Add a horizontal line to the plotted reads if we're plotting e-values and a zero e-value was found. @param readsAx: A Matplotlib sub-plot instance, as returned by matplotlib.pyplot.subplot. """

        # If we're using bit scores, there's nothing to do.
        if self.scoreClass is HigherIsBetterScore:
            return

        if self._zeroEValueFound:
            readsAx.axhline(y=self._maxConvertedEValue + 0.5, color='#cccccc',
                            linewidth=0.5)