class ActiveRecord::Reflection::ThroughReflection

def through_reflection


# =>
tags_reflection.through_reflection
tags_reflection = Post.reflect_on_association(:tags)

end
has_many :tags, through: :taggings
has_many :taggings
class Post < ActiveRecord::Base

of a HasManyThrough or HasOneThrough association.
Returns the AssociationReflection object specified in the :through option 
def through_reflection
  active_record._reflect_on_association(options[:through])
end