Url.kt

// 1st by "const"
@file:JvmName("Url")
const val URL_BASE: String = "http://github.com"
const val URL_USER: String = "$URL_BASE/user"

// 2nd by "companion"
class Url {
  companion object {
    @JvmField val URL_BASE: String = "http://github.com"
    @JvmField val URL_USER: String = "$URL_BASE/user"
  }
}