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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 _on_loop_start(self, variables):
 """ performs on-loop-start actions like callbacks variables contains local namespace variables. Parameters --------- variables : dict of available variables Returns ------- None """

        for callback in self.callbacks:
            if hasattr(callback, 'on_loop_start'):
                self.logs_[str(callback)].append(callback.on_loop_start(**variables))