code: def array_from_adus_to_electrons_per_second(self, array, gain):
          
          if array is not None:
              return np.divide(gain * array, self.exposure_time_map)
          else:
              return None
docs: For an array (in counts) and an exposure time mappers, convert the array to units electrons per second
  
          Parameters
          ----------
          array : ndarray
              The array the values are to be converted from counts to electrons per second.