def notes(element_key)
      parameter = { basic_auth: @auth }

      response = self.class.get("/elements/#{element_key}/notes", parameter)
      if response.success?
        search_response_header = SearchResponseHeader.new(response)
        search_response_header.elementList
      end
    end
def notes(element_key)
      parameter = { basic_auth: @auth }

      response = self.class.get("/elements/#{element_key}/notes", parameter)
      if response.success?
        search_response_header = SearchResponseHeader.new(response)
        search_response_header.elementList
      end
    end
It returns the notes of an element if anything are given
 Notes list can be empty
 It returns nil if no element with this elementKey was found