Yes it is possible. Sort of:
<gwt:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder' xmlns:gwt='urn:import:com.google.gwt.user.client.ui' xmlns:foo='url:import:com.foo.your.package.here'> <gwt:HTMLPanel> <foo:YourUiBinderStuff /> </gwt:HTMLPanel> </gwt:UiBinder>
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