code: def time_track(self, absolute_time=False, accuracy='ns'):
          
  
          try:
              increment = self.property('wf_increment')
              offset = self.property('wf_start_offset')
          except KeyError:
              raise KeyError("Object does not have time properties available.")
  
          periods = len(self._data)
  
          relative_time = np.linspace(
              offset,
              offset + (periods - 1) * increment,
              periods)
  
          if not absolute_time:
              return relative_time
  
          try:
              start_time = self.property('wf_start_time')
          except KeyError:
              raise KeyError(
                  "Object does not have start time property available.")
  
          try:
              unit_correction = {
                  's': 1e0,
                  'ms': 1e3,
                  'us': 1e6,
                  'ns': 1e9,
              }[accuracy]
          except KeyError:
              raise KeyError("Invalid accuracy: {0}".format(accuracy))
  
          # Because numpy only knows ints as its date datatype,
          # convert to accuracy.
          time_type = "timedelta64[{0}]".format(accuracy)
          return (np.datetime64(start_time) +
                  (relative_time * unit_correction).astype(time_type))
docs: Return an array of time or the independent variable for this channel
  
          This depends on the object having the wf_increment
          and wf_start_offset properties defined.
          Note that wf_start_offset is usually zero for time-series data.
          If you have time-series data channels with different start times,
          you should use the absolute time or calculate the time offsets using
          the wf_start_time property.
  
          For larger timespans, the accuracy setting should be set lower.
          The default setting is 'ns', which has a timespan of
          [1678 AD, 2262 AD]. For the exact ranges, refer to
          http://docs.scipy.org/doc/numpy/reference/arrays.datetime.html
          section "Datetime Units".
  
          :param absolute_time: Whether the returned time values are absolute
              times rather than relative to the start time. If true, the
              wf_start_time property must be set.
          :param accuracy: The accuracy of the returned datetime64 array.
          :rtype: NumPy array.
          :raises: KeyError if required properties aren't found