interface MonadTrans : ((Type -> Type) -> Type -> Type) -> TypeA monad transformer is a type that can wrap an inner monad, extending it
with additional abilities.
lift : Monad m => m a -> t m aLift a computation from the inner monad to the transformed monad.
MonadTrans (EitherT e)MonadTrans MaybeTMonadTrans (RWST r w s)MonadTrans (ReaderT stateType)MonadTrans (StateT stateType)MonadTrans (WriterT w)lift : MonadTrans t => Monad m => m a -> t m aLift a computation from the inner monad to the transformed monad.