app/serializers/pens_model_micro_cluster_serializer.rb
class PensModelMicroClusterSerializer
include JSONAPI::Serializer
has_many :model_variants, serializer: PensModelVariantSerializer
belongs_to :model,
id_method_name: :pens_model_id,
serializer: PensModelSerializer
attribute :simplified_brand
attribute :simplified_model
end