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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 _getBusVoltageLambdaSensor(self):
 """ Returns an array of length nb where each value is the sum of the Lagrangian multipliers on the upper and the negative of the Lagrangian multipliers on the lower voltage limits. """

        muVmin = array([b.mu_vmin for b in self.market.case.connected_buses])
        muVmax = array([b.mu_vmax for b in self.market.case.connected_buses])
        muVmin = -1.0 * muVmin
        diff = muVmin + muVmax
        return diff