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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 ramp_up_sp(self):
 """ Writing sets the ramp up setpoint. Reading returns the current value. Units are in milliseconds and must be positive. When set to a non-zero value, the motor speed will increase from 0 to 100% of `max_speed` over the span of this setpoint. The actual ramp time is the ratio of the difference between the `speed_sp` and the current `speed` and max_speed multiplied by `ramp_up_sp`. """

        self._ramp_up_sp, value = self.get_attr_int(self._ramp_up_sp, 'ramp_up_sp')
        return value