Need help how to test 

Dear Sir,
I am really exited seeing your article and creating microsservice testing of yours.

But 
{
  "name": "srikanth",
  "plot": "india",
  "genres": [
    "telugu"
  ],
  "casts_id": [
    0
  ]
}

But error coming cast_id 0 NOT a valid 

Please suggest what i should enter to test 

Thanks 
srikanth 
