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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 assert_valid_schema(schema: GraphQLSchema) -> None: """Utility function which asserts a schema is valid. Throws a TypeError if the schema is invalid. """

    errors = validate_schema(schema)
    if errors:
        raise TypeError("\n\n".join(error.message for error in errors))