def domain(word)
      check_params(word)

      arg1 = ['Wort', word]
      answer = query(@cl_Sachgebiet, arg1)

      get_answer(answer)
    end
def domain(word)
      check_params(word)

      arg1 = ['Wort', word]
      answer = query(@cl_Sachgebiet, arg1)

      get_answer(answer)
    end
Returns categories for a given input word as an array:
   api.domain("Michael") => ["Vorname", "Nachname", "Männername"]
--
 Is it a good name? all names are in English, but here..
 let's call it domain, not sachgebiet