src/vs/workbench/contrib/output/common/outputChannelModel.ts/FileOutputChannelModel/getContentToUpdate
class FileOutputChannelModel:	private async getContentToUpdate(): Promise<VSBuffer> {
		const content = await this.fileService.readFile(this.file, { position: this.endOffset });
		this.etag = content.etag;
		return content.value;
	}