Transform class diagram showing the core abstraction for Node.js stream transformations in TypeScript. The diagram defines BufferEncoding type union (ascii, utf8, utf-16le, base64, etc.), TransformCallback function signature, and the Transform class with its _transform method signature. This pattern is essential for developers implementing custom data processors, compression handlers, or protocol parsers that operate on streaming data. Fork and customize this diagram to document your own Transform subclasses or integrate it into architecture documentation for stream-based applications.