class ActiveModelSerializers::Adapter::JsonApi

def data_for(serializer, include_slice)
  data = serializer.fetch(self) do
    resource_object = ResourceIdentifier.new(serializer, instance_options).as_json
    break nil if resource_object.nil?
    requested_fields = fieldset && fieldset.fields_for(resource_object[:type])
    attributes = attributes_for(serializer, requested_fields)
    resource_object[:attributes] = attributes if attributes.any?
    resource_object
  end
  data.tap do |resource_object|
    next if resource_object.nil?
    # NOTE(BF): the attributes are cached above, separately from the relationships, below.
    requested_associations = fieldset.fields_for(resource_object[:type]) || '*'
    relationships = relationships_for(serializer, requested_associations, include_slice)
    resource_object[:relationships] = relationships if relationships.any?
  end
end