Outdated design documentation?

[SteveLauC]

Hi, I am playing with the project, and looks like the design doc is a bit outdated? It says that:

Unlike the standard library, the File type does not expose a byte stream
directly. Instead, the caller requests a read or write stream, making it
possible to support multiple concurrent streams. Each file stream maintains its
cursor and issues positional read and write operations based on the cursor.

But looks like the File type does not have such a read_stream() or write_stream() method?