code: def data(self):
          
          if self._data is None:
              # self._data is None if data segment is empty
              return np.empty((0, 1))
          if self._data_scaled is None:
              scale = scaling.get_scaling(self)
              if scale is None:
                  self._data_scaled = self._data
              else:
                  self._data_scaled = scale.scale(self._data)
  
          return self._data_scaled
docs: NumPy array containing data if there is data for this object,
          otherwise None.