<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def parsing(**kwargs):
 """ Context manager for overriding the default validator parsing rules for the following code block. """


    from .validators import Object
    with _VALIDATOR_FACTORIES_LOCK:
        old_values = {}
        for key, value in iteritems(kwargs):
            if value is not None:
                attr = key.upper()
                old_values[key] = getattr(Object, attr)
                setattr(Object, attr, value)
        try:
            yield
        finally:
            for key, value in iteritems(kwargs):
                if value is not None:
                    setattr(Object, key.upper(), old_values[key])