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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 should_update(stack):
 """Tests whether a stack should be submitted for updates to CF. Args: stack (:class:`stacker.stack.Stack`):
 The stack object to check. Returns: bool: If the stack should be updated, return True. """

    if stack.locked:
        if not stack.force:
            logger.debug("Stack %s locked and not in --force list. "
                         "Refusing to update.", stack.name)
            return False
        else:
            logger.debug("Stack %s locked, but is in --force "
                         "list.", stack.name)
    return True