---
title: "Incomplete Library Class"
type: "code-smell"
slug: "incomplete-library-class"
url: "http://localhost:3000/en/smells/incomplete-library-class.md"
category: "Other Smells"
description: "Sooner or later, libraries stop meeting user needs. The only solution to the problem—changing the library—is often impossible since the library is read-only."
---
# Incomplete Library Class

> Sooner or later, libraries stop meeting user needs. The only solution to the problem—changing the library—is often impossible since the library is read-only.

## Signs and Symptoms

Sooner or later, [libraries](https://en.wikipedia.org/wiki/Library%5F%28computing%29) stop meeting user needs. The only solution to the problem—changing the library—is often impossible since the library is read-only.

## Reasons for the Problem

The author of the library hasn’t provided the features you need or has refused to implement them.

## Payoff

* Reduces code duplication (instead of creating your own library from scratch, you can still piggy-back off an existing one).
## Relations

**Treated by**

- [Introduce Foreign Method](/en/introduce-foreign-method.md)
- [Introduce Local Extension](/en/introduce-local-extension.md)