Search for a defintion with `keyword` `name`
        Search the module and its submodules.

def search_definition(self, module, keyword, arg):
        """Search for a defintion with `keyword` `name`
        Search the module and its submodules."""
        r = module.search_one(keyword, arg)
        if r is not None:
            return r
        for i in module.search('include'):
            modulename = i.arg
            m = self.ctx.search_module(i.pos, modulename)
            if m is not None:
                r = m.search_one(keyword, arg)
                if r is not None:
                    return r
        return None