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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 product_set_path(cls, project, location, product_set):
 """Return a fully-qualified product_set string."""

        return google.api_core.path_template.expand(
            "projects/{project}/locations/{location}/productSets/{product_set}",
            project=project,
            location=location,
            product_set=product_set,
        )