lib/paper_trail/version_concern.rb
def version_limit
      if self.class.item_subtype_column_present?
        klass = (item_subtype || item_type).constantize
        if klass&.paper_trail_options&.key?(:limit)
          return klass.paper_trail_options[:limit]
        end
      end
      PaperTrail.config.version_limit
    end
def version_limit
      if self.class.item_subtype_column_present?
        klass = (item_subtype || item_type).constantize
        if klass&.paper_trail_options&.key?(:limit)
          return klass.paper_trail_options[:limit]
        end
      end
      PaperTrail.config.version_limit
    end
See docs section 2.e. Limiting the Number of Versions Created.
 The version limit can be global or per-model.

 @api private

 TODO: Duplication: similar `constantize` in Reifier#version_reification_class