IReadBufferState<TReadBufferState, TStream>
                    interface IReadBufferState<TReadBufferState, TStream> : IDisposable where TReadBufferState : struct, IReadBufferState<TReadBufferState, TStream>
                
                
ValueTask<TReadBufferState> ReadAsync(TStream utf8Json, CancellationToken cancellationToken, bool fillBuffer = true)