class ActiveRecord::Associations::Builder::HasMany

def self.valid_options(options)
  valid = super + [:counter_cache, :join_table, :index_errors, :as, :through]
  valid += [:foreign_type] if options[:as]
  valid += [:source, :source_type, :disable_joins] if options[:through]
  valid += [:ensuring_owner_was] if options[:dependent] == :destroy_async
  valid
end