def billOfMaterial(element_key, options = {})
      parameter = { query: options }
      parameter[:basic_auth] = @auth

      response = self.class.get("/elements/#{element_key}/bom", parameter)
      if response.success?
        bom_list = BomElementList.new(response)
        return bom_list.bomElementList
      end
    end
def billOfMaterial(element_key, options = {})
      parameter = { query: options }
      parameter[:basic_auth] = @auth

      response = self.class.get("/elements/#{element_key}/bom", parameter)
      if response.success?
        bom_list = BomElementList.new(response)
        return bom_list.bomElementList
      end
    end
Loads the bill of meterial on articles
 +options+ can have these values: size, page, attribute = ALL|NONE|GLOBALLISTER|SECONDARY|EXPLORER
 Returns a list of elements
 It returns nil if no element with this elementKey was found