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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 meta_changed(self, model, prop_name, info):
 """When the meta was changed, we have to set the dirty flag, as the changes are unsaved"""

        self.state_machine.marked_dirty = True
        msg = info.arg
        if model is not self and msg.change.startswith('sm_notification_'):  # Signal was caused by the root state
            # Emit state_meta_signal to inform observing controllers about changes made to the meta data within the
            # state machine
            # -> removes mark of "sm_notification_"-prepend to mark root-state msg forwarded to state machine label
            msg = msg._replace(change=msg.change.replace('sm_notification_', '', 1))
            self.state_meta_signal.emit(msg)