*  * **Shared channels:** read and write a file channel that's shared between
 * multiple operators. Note that although the underlying [FileChannel] may be shared,
 * each [FileOperator] should not be.
 */
internal class FileOperator(
  private val fileChannel: FileChannel,
) {
  /** Write [byteCount] bytes from [source] to the file at [pos]. */
  @Throws(IOException::class)
  fun write(
    pos: Long,