Problem with parsing tag(::HTMLText) in Gumbo

Sombody can help ? Why HTMLText stoped it ?

julia> using HTTP,Gumbo,AbstractTrees

julia> url=url="http://bbc.com";

julia> r=HTTP.request("GET", url; retries=4, cookies=true);

julia> doc=parsehtml(String(r.body));

julia> tag.(doc.root[:])
2-element Array{Symbol,1}:
 :head
 :body

julia>

julia> for elem in StatelessBFS(doc.root) println(tag(elem)) end
HTML
head
body
meta
meta
meta
title
script
meta
meta
meta
meta
meta
meta
meta
meta
meta
meta
link
link
link
link
link
link
meta
meta
link
script
script
script
script
script
script
script
link
script
script
style
script
script
script
script
script
script
script
script
script
script
script
script
script
script
script
link
script
script
script
link
script
script
noscript
div
div
div
div
script
script
div
header
div
div
script
script
script
script
div
script
script
script
script
script
script
ERROR: MethodError: no method matching tag(::HTMLText)
Closest candidates are:
  tag(::HTMLElement{T}) where T at C:\Users\Julai1_0_5\.julia\packages\Gumbo\G7Qbw\src\manipulation.jl:6
Stacktrace:
 [1] top-level scope at .\REPL[6]:1 [inlined]
 [2] top-level scope at .\none:0

julia>

Paul