class ReeDto::BuildDto

def call(&proc)
  klass = get_caller
  klass.include DtoInstanceMethods
  klass.extend DtoClassMethods
  builder = DtoBuilder.new(self)
  builder.instance_exec(&proc)
  klass.send(:set_fields, builder.fields)
  klass.send(:set_collections, builder.collections)
  builder.fields.each do |field|
    klass.instance_exec do
      contract None => field.contract
    end
    klass.define_method field.name do
      get_value(field.name)
    end
    if field.setter
      klass.instance_exec do
        contract field.contract => field.contract
      end
      klass.define_method :"#{field.name}=" do |val|
        set_value(field.name, val)
      end
    end
  end
  builder.collections.each do |collection|
    col_class = build_dto_collection_class(klass, collection.name, collection.contract)
    col_class.class_exec(&collection.filter_proc) if collection.filter_proc
    klass.instance_exec do
      contract ArrayOf[collection.contract] => DtoCollection
    end
    klass.define_method "#{collection.name}=" do |list|
      col = send(collection.name)
      list.each do |item|
        col.add(item)
      end
      col
    end
    klass.instance_exec do
      contract None => DtoCollection
    end
    klass.define_method collection.name do
      @collections ||= {}
      @collections[collection.name] ||= col_class.new(
        collection.name, collection.contract, klass
      )
    end
  end
  nil
end