class ActiveModel::Serializer

def associations_hash(adapter_options, options, adapter_instance)
  include_directive = options.fetch(:include_directive)
  include_slice = options[:include_slice]
  associations(include_directive, include_slice).each_with_object({}) do |association, relationships|
    adapter_opts = adapter_options.merge(include_directive: include_directive[association.key], adapter_instance: adapter_instance)
    relationships[association.key] = association.serializable_hash(adapter_opts, adapter_instance)
  end
end