chore: checkpoint before Python removal

vendor/schemars/tests/dereference.rs

@@ -0,0 +1,23 @@
+use schemars::{r#gen::SchemaGenerator, JsonSchema};
+use std::ptr;
+
+#[allow(dead_code)]
+#[derive(JsonSchema)]
+struct Struct {
+    foo: i32,
+    bar: bool,
+}
+
+#[test]
+fn dereference_struct() {
+    let mut generator = SchemaGenerator::default();
+    let struct_ref_schema = generator.subschema_for::<Struct>();
+    let struct_schema = generator.definitions().get(&<Struct>::schema_name()).unwrap();
+
+    assert!(struct_ref_schema.is_ref());
+    assert!(!struct_schema.is_ref());
+
+    let dereferenced = generator.dereference(&struct_ref_schema);
+    assert!(dereferenced.is_some());
+    assert!(ptr::eq(dereferenced.unwrap(), struct_schema));
+}