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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def spawn_isolated_child(econtext):
 """ For helper functions executed in the fork parent context, arrange for the context's router to be upgraded as necessary and for a new child to be prepared. The actual fork occurs from the 'virginal fork parent', which does not have any Ansible modules loaded prior to fork, to avoid conflicts resulting from custom module_utils paths. """

    mitogen.parent.upgrade_router(econtext)
    if FORK_SUPPORTED:
        context = econtext.router.fork()
    else:
        context = econtext.router.local()
    LOG.debug('create_fork_child() -> %r', context)
    return context