How to expose AudioProcessingImpl methods so that they can be called from a flutter webrtc app?

Question

I want to declare 5 methods in the AudioProcessingImpl class. This class is defined in audio_processing_impl.h in ..\src\modules\audio_processing.

The methods I want to implement have the following prototypes:

• float GetThresholdLevel(void);
• void SetThresholdLevel(float level);
• bool AudioGateGet(void);
• void AudioGateSet(bool enabled);
• float GetCurrentLevel(void);

How do I expose those methods so that they can be called from a flutter webrtc app?