EncodedJSValue JSC_HOST_CALL jsTestJSBuiltinConstructorPrototypeFunctionTestCustomFunction(ExecState* state)
{
    JSValue thisValue = state->thisValue();
    JSTestJSBuiltinConstructor* castedThis = jsDynamicCast<JSTestJSBuiltinConstructor*>(thisValue);
    if (UNLIKELY(!castedThis))
        return throwThisTypeError(*state, "TestJSBuiltinConstructor", "testCustomFunction");
    ASSERT_GC_OBJECT_INHERITS(castedThis, JSTestJSBuiltinConstructor::info());
    return JSValue::encode(castedThis->testCustomFunction(*state));
}