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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 constant(self, name, value):
 """Declare and set a project global constant. Project global constants are normal variables but should not be changed. They are applied to every child Jamfile."""

        assert is_iterable_typed(name, basestring)
        assert is_iterable_typed(value, basestring)
        self.registry.current().add_constant(name[0], value)