lib/tabletastic/helper.rb
def default_class_for(collection)
      if collection.respond_to?(:klass) # ActiveRecord::Relation
        collection.klass
      elsif !collection.empty?
        collection.first.class
      end
    end
def default_class_for(collection)
      if collection.respond_to?(:klass) # ActiveRecord::Relation
        collection.klass
      elsif !collection.empty?
        collection.first.class
      end
    end
Finds the class representing the objects within the collection