You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: calendar.rb
    path of file: ./repos/openproject/modules/calendar/spec/support/pages
    
    the code of the file until where you have to start completion: #-- copyright
# OpenProject is an open 
    
    def add_item(start_date, end_date)
      start_container = date_container start_date
      end_container = date_container end_date

      drag_n_drop_element(from: start_container, to: end_container)

      ::Pages::SplitWorkPackageCreate.new project:
    end