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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 get_placeholder_data(self, request, obj=None):
 """ Return the data of the placeholder fields. """

        # Return all placeholder fields in the model.
        if not hasattr(self.model, '_meta_placeholder_fields'):
            return []

        data = []
        for name, field in self.model._meta_placeholder_fields.items():
            assert isinstance(field, PlaceholderField)
            data.append(PlaceholderData(
                slot=field.slot,
                title=field.verbose_name.capitalize(),
                fallback_language=None,  # Information cant' be known by "render_placeholder" in the template.
            ))

        return data