Why function scala.reflect.runtime.universe.classTag[T] is missing?

I'm using apache Spark and one of my subroutine is to check if T: ClassTag of an RDD[T: ClassTag] is a subclass of Map.

I've checked many source on scala reflection and they all suggest the following code:

import scala.reflect.runtime.universe._
if classTag[T] <:< classTag[Map[_,_]] {do something...}

however the classTag function seems to be missing, I only see typeOf and weakTypeOf which obviously doesn't work here (because of type erasure: ClassTag of an RDD carries far less information than a TypeTag). Is it moved somewhere else in a later scala version? I'm using 2.10.4

Thanks a lot!