Gets the time and voltage data.

        Parameters
        ----------
        timeStart : float, optional
            The time get data from.
            By default it uses the first time point
        timeEnd : float, optional
            The time to finish getting data from.
            By default it uses the last time point        

        Returns
        -------
        time : ndarray
                        array containing the value of time (in seconds) at which the
                        voltage is sampled
        voltage : ndarray
                        array containing the sampled voltages

def get_time_data(self, timeStart=None, timeEnd=None):
        """
        Gets the time and voltage data.

        Parameters
        ----------
        timeStart : float, optional
            The time get data from.
            By default it uses the first time point
        timeEnd : float, optional
            The time to finish getting data from.
            By default it uses the last time point        

        Returns
        -------
        time : ndarray
                        array containing the value of time (in seconds) at which the
                        voltage is sampled
        voltage : ndarray
                        array containing the sampled voltages
        """
        if timeStart == None:
            timeStart = self.timeStart
            
        if timeEnd == None:
            timeEnd = self.timeEnd

        time = self.time.get_array()
            
        StartIndex = _np.where(time == take_closest(time, timeStart))[0][0]
        EndIndex = _np.where(time == take_closest(time, timeEnd))[0][0]

        if EndIndex == len(time) - 1:
            EndIndex = EndIndex + 1 # so that it does not remove the last element

        return time[StartIndex:EndIndex], self.voltage[StartIndex:EndIndex]