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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 changed(self, code_changed=False, value_changed=False):
 """Inform dependents that this shaderobject has changed. """

        for d in self._dependents:
            d._dep_changed(self, code_changed=code_changed,
                           value_changed=value_changed)