class ActiveModel::Attribute::FromDatabase

def forgetting_assignment
  # If this attribute was not persisted (with a `value_for_database`
  # that might differ from `value_before_type_cast`) and `value` has not
  # changed in place, we can use the existing `value_before_type_cast`
  # to avoid deserialize / cast / serialize calls from computing the new
  # attribute's `value_before_type_cast`.
  if !defined?(@value_for_database) && !changed_in_place?
    with_value_from_database(value_before_type_cast)
  else
    super
  end
end