#[test]
    fn test_coerce_union() -> Result<()> {
        let left_plan = Arc::new(LogicalPlan::EmptyRelation(EmptyRelation {
            produce_one_row: false,
            schema: Arc::new(
                DFSchema::try_from_qualified_schema(
                    TableReference::full("datafusion", "test", "foo"),
                    &Schema::new(vec![Field::new("a", DataType::Int32, false)]),
                )
                .unwrap(),
            ),
        }));
        let right_plan = Arc::new(LogicalPlan::EmptyRelation(EmptyRelation {
            produce_one_row: false,
            schema: Arc::new(
                DFSchema::try_from_qualified_schema(
                    TableReference::full("datafusion", "test", "foo"),
                    &Schema::new(vec![Field::new("a", DataType::Int64, false)]),
                )
                .unwrap(),
            ),
        }));
        let union = LogicalPlan::Union(Union::try_new_with_loose_types(vec![
            left_plan, right_plan,
        ])?);
        let analyzed_union = Analyzer::with_rules(vec![Arc::new(TypeCoercion::new())])
            .execute_and_check(union, &ConfigOptions::default(), |_, _| {})?;
        let top_level_plan = LogicalPlan::Projection(Projection::try_new(
            vec![wildcard()],
            Arc::new(analyzed_union),
        )?);
        let expanded_plan =
            Analyzer::with_rules(vec![Arc::new(ExpandWildcardRule::new())])
                .execute_and_check(
                    top_level_plan,
                    &ConfigOptions::default(),
                    |_, _| {},
                )?;

        let expected = "Projection: datafusion.test.foo.a\n  Union\n    Projection: CAST(datafusion.test.foo.a AS Int64) AS a\n      EmptyRelation\n    EmptyRelation";
        assert_analyzed_plan_eq(Arc::new(TypeCoercion::new()), expanded_plan, expected)
    }