def get_default_value(self):
        """Instantiate a default value instance.

        This is called when the containing HasTraits classes'
        :meth:`__new__` method is called to ensure that a unique instance
        is created for each HasTraits instance.
        """
        dv  = self.default_value
        if isinstance(dv, DefaultValueGenerator):
            return dv.generate(self.klass)
        else:
            return dv
Instantiate a default value instance.

        This is called when the containing HasTraits classes'
        :meth:`__new__` method is called to ensure that a unique instance
        is created for each HasTraits instance.