GWT: celltable column header's tooltip not appearing correctly -

i using tool tip gwt celltable column headers .

the problem can see first work of tooltip , not second word after space, example if in tool tip write "hello world"

it appears "hello"

the word after space not appearing ..

thats code using

       celltable.addcolumn(mycolumn, safehtmlutils.fromsafeconstant("<span title="+"heloo world"+">"+constants.xvd+"</span>")); 

so in case tool tip says"heloo" instead of "hello world"

as can see in attached image

maybe like:

"<span title=\"heloo world\">"+constants.xvd+"</span>" 

will work ? (escaping ")