app/serializers/trade/shipment_serializer.rb
class Trade::ShipmentSerializer < ActiveModel::Serializer
attributes :id, :appendix, :quantity, :year,
:term_id, :unit_id, :purpose_id, :source_id,
:taxon_concept_id, :reported_taxon_concept_id,
:importer_id, :exporter_id, :reporter_type, :country_of_origin_id,
:import_permit_number, :export_permit_number, :origin_permit_number,
:legacy_shipment_number, :warnings
has_one :taxon_concept, :serializer => Trade::TaxonConceptSerializer
has_one :reported_taxon_concept, :serializer => Trade::TaxonConceptSerializer
end