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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 trim_core(self):
 """ This method trims a previously extracted unsatisfiable core at most a given number of times. If a fixed point is reached before that, the method returns. """


        for i in range(self.trim):
            # call solver with core assumption only
            # it must return 'unsatisfiable'
            self.oracle.solve(assumptions=self.core)

            # extract a new core
            new_core = self.oracle.get_core()

            if len(new_core) == len(self.core):
                # stop if new core is not better than the previous one
                break

            # otherwise, update core
            self.core = new_core