<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 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