twitter bootstrap - Increasing the height of root panel in gwt -

i have html panel , want add html panel browser screen hence used rootpanel.get().add(htmlpanel);. space between starting of screen , first widget in html panel (as in image). tried setting rootpanel.get().setheight("100%") , rootpanel.get().setsize("100%","100%") doesn't seem work please want remove space , widget starts beginning.

this padding added gwt bootstrap navbar widget. see note in javadoc:

note: assume people use responsivenavbar, so, automatically add padding-top: 50px in body.if don't want this, have put padding-top: 0px; manually in document body tag.

see https://github.com/gwtbootstrap/gwt-bootstrap/issues/120