class ActiveModelSerializers::Adapter::Json

def meta
  instance_options.fetch(:meta, nil)
end

def meta_key
  instance_options.fetch(:meta_key, 'meta'.freeze)
end

def serializable_hash(options = nil)
  options = serialization_options(options)
  serialized_hash = { root => Attributes.new(serializer, instance_options).serializable_hash(options) }
  serialized_hash[meta_key] = meta unless meta.blank?
  self.class.transform_key_casing!(serialized_hash, instance_options)
end