Link the *other* module into this one.  The *other* module will
        be destroyed unless *preserve* is true.

def link_in(self, other, preserve=False):
        """
        Link the *other* module into this one.  The *other* module will
        be destroyed unless *preserve* is true.
        """
        if preserve:
            other = other.clone()
        link_modules(self, other)