handle_structures.rb

# Handle the data structures
[
  ['distributionevent', 'distribution_events', DistributionEvent],
  ['storage', 'storages', Storage]
].each do |name, accessor, structure_class|
  data = product_data[name]
  self.send("#{accessor}=", (!data.nil? && data.size > 0) ? 
                              data.map { |d| structure_class.new d } : [])
end