def has_many(association_id, options = {}, &extension)
reflection = create_has_many_reflection(association_id, options, &extension)
configure_dependency_for_has_many(reflection)
if options[:through]
collection_reader_method(reflection, HasManyThroughAssociation)
else
add_multiple_associated_save_callbacks(reflection.name)
add_association_callbacks(reflection.name, reflection.options)
collection_accessor_methods(reflection, HasManyAssociation)
end
add_deprecated_api_for_has_many(reflection.name)
end