def import_indices(length)
      # Note that this method is defined in the parent Record class, where it is
      # used for most record types. However, because this record has two attributes
      # which contain an array of values, we use a custom import_indices method.
      ind = Array.new(length - NR_SURPLUS_ATTRIBUTES) { |i| i }
      # Override indices for field_ids and region_coeffs:
      ind[3] = [3, 5, 7, 9, 11, 13, 15, 17, 19, 21]
      ind[4] = [4, 6, 8, 10, 12, 14, 16, 18, 20, 22]
      ind[5, 6] = [23, 24]
      ind
    end
def import_indices(length)
      # Note that this method is defined in the parent Record class, where it is
      # used for most record types. However, because this record has two attributes
      # which contain an array of values, we use a custom import_indices method.
      ind = Array.new(length - NR_SURPLUS_ATTRIBUTES) { |i| i }
      # Override indices for field_ids and region_coeffs:
      ind[3] = [3, 5, 7, 9, 11, 13, 15, 17, 19, 21]
      ind[4] = [4, 6, 8, 10, 12, 14, 16, 18, 20, 22]
      ind[5, 6] = [23, 24]
      ind
    end
Gives an array of indices indicating where the attributes of this record gets its
 values from in the comma separated string which the instance is created from.

 @param [Integer] length the number of elements to create in the indices array