[new_pymtl] add value check to .next
[new_pymtl] add value check to .next

jck/pymtl,12yujim/pymtl,cornell-brg/pymtl,cornell-brg/pymtl,Glyfina-Fernando/pymtl,jck/pymtl,cfelton/pymtl,jjffryan/pymtl,12yujim/pymtl,jjffryan/pymtl,Glyfina-Fernando/pymtl,12yujim/pymtl,tj93/pymtl,jjffryan/pymtl,cfelton/pymtl,tj93/pymtl,jck/pymtl,cfelton/pymtl,cornell-brg/pymtl,tj93/pymtl,Glyfina-Fernando/pymtl