def __getOptimizedMetricLabel(self):
matchingKeys = matchPatterns([self._optimizeKeyPattern],<EOL>self._getMetricLabels())<EOL>if len(matchingKeys) == <NUM_LIT:0>:<EOL><INDENT>raise Exception("<STR_LIT>"<EOL>"<STR_LIT>" %(self._optimizeKeyPattern, self._getMetricLabels()))<EOL><DEDENT>elif len(matchingKeys) > <NUM_LIT:1>:<EOL><INDENT>raise Exception("<STR_LIT>"<EOL>"<STR_LIT>" % (self._optimizeKeyPattern, matchingKeys))<EOL><DEDENT>return matchingKeys[<NUM_LIT:0>]<EOL>
Get the label for the metric being optimized. This function also caches
        the label in the instance variable self._optimizedMetricLabel

        Parameters:
        -----------------------------------------------------------------------
        metricLabels:   A sequence of all the labels being computed for this model

        Returns:        The label for the metric being optmized over