def prepare_revision
      return if new_record?
      if (respond_to?(:fragments_attributes_changed) && fragments_attributes_changed) ||
        !(changed & revision_fields).empty?
        self.revision_data = revision_fields.each_with_object({}) do |field, c|
          c[field] = send("#{field}_was")
        end
      end
    end
def prepare_revision
      return if new_record?
      if (respond_to?(:fragments_attributes_changed) && fragments_attributes_changed) ||
        !(changed & revision_fields).empty?
        self.revision_data = revision_fields.each_with_object({}) do |field, c|
          c[field] = send("#{field}_was")
        end
      end
    end
Preparing revision data. A bit of a special thing to grab page blocks