Cities as JSON

All used data is available on Correios, Google Maps and Open Street Maps.

Is there any methods that I can use?

No. It is pure JSON and I have no intention to develop methods to manipulate this data.

Following the KISS statements, it it simple as possible, the basic schema is below.

[
  {
    "name": "Acre",
    "cities": [
      {"name": "Rio Branco"}
    ]
  }
]

Just open an issue and I'll fix.