def attributes_for_code(code, code_system)
      @attributes.find_all { |e| e.send(:code) == code && e.send(:code_obj).send(:system) == code_system }
    end
def attributes_for_code(code, code_system)
      @attributes.find_all { |e| e.send(:code) == code && e.send(:code_obj).send(:system) == code_system }
    end
Get specific attributes by code.
 @param [String] code the attribute code
 @param [String] code_system the attribute code system
 @return [Array#Attribute] the matching attributes, raises an Exception if not found