outr/scarango

Someone could tell me?, please why I get this error:

exception during macro expansion: Response processing error
[error]                   .query ( aql"FOR p IN testChangos RETURN p" )
[error]                            ^

with this code:

val db = new ArangoDB(credentials = Some(Credentials("root", "jctaurys")))
  case class User( name: String, age: Int, observation: String, _id: Id[User] = User.id() ) extends Document[User]

  object User extends DocumentModel[User] {
      override def indexes: List[Index] = Nil      
      override val collectionName: String = "testChangos"
      override val serialization: Serialization[User] = Serialization.auto[User]
  }

  object database extends Graph(databaseName = "example") {   
      val testChangos: DocumentCollection[User] = vertex[User]
  }

  for {
      _ <- database.init()
      result <- database.testChangos
                  .query ( aql"FOR p IN testChangos RETURN p" )         
                  .results.map { users =>  println ( users.map ( _.name ).toSet ) }
  } yield {   println ( result )  }