Working extendable

src/ZodSchemaClass.ts

@@ -1,6 +1,7 @@
 import { expression } from "@thilawyn/traitify-ts"
 import { AbstractClass } from "type-fest"
 import { z } from "zod"
+import { ExtendableZodSchemaObject } from "./traits/ExtendableZodSchemaObject"
 import { InstantiableZodSchemaObject } from "./traits/InstantiableZodSchemaObject"
 import { Extend, StaticMembers } from "./util"
 
@@ -32,7 +33,10 @@ export function ZodSchemaClassOf<
                 Object.assign(this, values)
             }
         })
-        .expresses(InstantiableZodSchemaObject)
+        .expresses(
+            InstantiableZodSchemaObject,
+            ExtendableZodSchemaObject,
+        )
         .build()
 
     return exp.extends as AbstractClass<