src/vs/workbench/api/common/extHostFileSystem.ts/ExtHostFileSystem/$writeFile
class ExtHostFileSystem:	$writeFile(handle: number, resource: UriComponents, content: VSBuffer, opts: files.IFileWriteOptions): Promise<void> {
		return Promise.resolve(this._getFsProvider(handle).writeFile(URI.revive(resource), content.buffer, opts));
	}