Json decoder for custom extensions

// here we add custom extension to the web request so that it will have the following header:
// "Accept: application/json;profile=my-profile"

// build.sbt
libraryDependencies ++= Seq(
  "org.slf4j" % "slf4j-nop" % "1.7.21",
  "io.circe" %% "circe-generic" % "0.10.0",
  "org.http4s" %% "http4s-circe" % "0.18.23",
  "org.http4s" %% "http4s-blaze-client" % "0.18.23"
)

// Hello.scala:
import scala.language.higherKinds
import cats.Monad
import cats.effect.{Effect, IO}
import io.circe.Decoder
import org.http4s._
import org.http4s.client.blaze.Http1Client
import org.http4s.circe._
import io.circe.generic.semiauto._

object Hello extends App {
  case class User(name: String)
  implicit val userDecoder: Decoder[User] = deriveDecoder

  def jsonExtensionsDecoder[F[_]: Monad: Effect, A](extensions: Map[String, String])
                                                   (implicit decoder: Decoder[A]): EntityDecoder[F, A] = {
    new EntityDecoder[F, A] {
      override def decode(msg: Message[F], strict: Boolean): DecodeResult[F, A] = jsonOf[F, A].decode(msg, strict)
      override def consumes: Set[MediaRange] = Set(MediaType.`application/json`.withExtensions(extensions))
    }
  }

  val httpClient = Http1Client[IO]().unsafeRunSync()
  val header = Header("x", "y")
  val usersIO = httpClient.expect(Request[IO](uri = Uri(path = "https://google.com"), headers = Headers(header)))(
    jsonExtensionsDecoder[IO, Seq[User]](Map("profile" -> "my-profile"))
  )
  val users = usersIO.unsafeRunSync()

  println(s"Users: $users")
}