Low-level, unsafe operations. Clients are responsible for resource-safety
when using these.
final case classWrite(h: WriteHandle, chunk: slamdata.Predef.Vector[Data]) extends WriteFile[slamdata.Predef.Vector[FileSystemError]] with Product with Serializable
final case classWriteHandle(file: AFile, id: slamdata.Predef.Long) extends Product with Serializable