def setUnjellyableForClass(classname, unjellyable):
    """
    Set which local class will represent a remote type.

    If you have written a Copyable class that you expect your client to be
    receiving, write a local "copy" class to represent it, then call::

        jellier.setUnjellyableForClass('module.package.Class', MyCopier).

    Call this at the module level immediately after its class
    definition. MyCopier should be a subclass of RemoteCopy.

    The classname may be a special tag returned by
    'Copyable.getTypeToCopyFor' rather than an actual classname.

    This call is also for cached classes, since there will be no
    overlap.  The rules are the same.
    """

    global unjellyableRegistry
    classname = _maybeClass(classname)
    unjellyableRegistry[classname] = unjellyable
    globalSecurity.allowTypes(classname)

    Set which local class will represent a remote type.

    If you have written a Copyable class that you expect your client to be
    receiving, write a local "copy" class to represent it, then call::

        jellier.setUnjellyableForClass('module.package.Class', MyCopier).

    Call this at the module level immediately after its class
    definition. MyCopier should be a subclass of RemoteCopy.

    The classname may be a special tag returned by
    'Copyable.getTypeToCopyFor' rather than an actual classname.

    This call is also for cached classes, since there will be no
    overlap.  The rules are the same.
    
stackoverflow/venv/lib/python3.6/site-packages/twisted/spread/jelly.py