Constant HURRAY_ERR_NOT_COMPOSITE 

pub const HURRAY_ERR_NOT_COMPOSITE: HurrayStatus = -22;

A composite was asked for where there is none, or offered where one is required.

Its own code for the reason HURRAY_ERR_NOT_FOUND has one: a composite read on a plain tensor, or a plain tensor at the head of a composite write, is a question the caller asked wrongly — nothing about the stream or the file is wrong.