**Describe the bug** If the message type equals 'InternalLoaderMessage', the constant value "difference" is incorrect. It will lost some tokens. **To Reproduce** Steps to reproduce the behavior: 1. Use BingAIClient and send the message "Tell me a long story.". **Expected behavior** All tokens will passed to onProgress. **Screenshots**  **Node.js version (please complete the following information):** - OS: Windows - Version: v20.11.0 **Package version (please complete the following information):** - 1.37.0 **Additional context** N/A