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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 neurons(self):
 """ Return list of neuron indices. Parameters None Returns ------- list list of neuron indices See also -------- sqlite3.connect.cursor """

        self.cursor.execute('SELECT DISTINCT neuron FROM spikes ORDER BY neuron')
        sel = self.cursor.fetchall()
        return np.array(sel).flatten()