Provides a type-safe builder for mapping Java objects to Flutter method channel arguments, enabling efficient, readable construction of complex nested structures. Reusable as a standalone utility for any Flutter plugin on Android that needs to build arguments for method channels without raw Map casting.

Manages audio device routing (speaker, Bluetooth, wired headset) on Android with configurable audio mode, focus, and stream type. Uses a singleton with delegate pattern to adapt to audio device changes. Extractable as a reusable audio routing module for any Android app requiring fine-grained audio output control.

Provides thread-safe replacement of remote tracks with atomic checks for same track ID and kind, preventing duplicate track events. Depends only on a minimal StateProvider interface. This pattern is directly reusable in any real-time communication plugin that needs to update tracks concurrently.

Implements end-to-end encryption for video/audio frames using AES-GCM with key ratcheting and per-participant key management. The architecture separates FrameCryptor and KeyProvider, with event queuing for async state changes. Although coupled to the FlutterWebRTCBase, the overall design pattern (encrypt/decrypt with key ring and ratchet) can be extracted as a reusable E2EE module for custom WebRTC implementations.