curl --request POST \
  --url https://api.example.com/EXPERIMENTAL_maintenance_windows \
  --header 'Content-Type: application/json' \
  --data '
{
  "method": "EXPERIMENTAL_maintenance_windows",
  "params": {
    "account_id": "<string>"
  },
  "id": "dontcare",
  "jsonrpc": "2.0"
}
'

{
  "result": [
    {
      "end": 1,
      "start": 1
    }
  ],
  "id": "<string>",
  "jsonrpc": "<string>"
}