From your link: "This enables the constitution to be easily changed as no provisions are formally entrenched."
It doesn't look like a duck, it doesn't quack like a duck, yet you insist that this goose-shaped creature is a duck.
I've heard it said that they have a constitution but it's written in pencil...
>It doesn't look like a duck
Some special amendment procedure is not the only or even defining feature of constitutional law. There is non-constitutional law that has this property and there is constitutional law that does not.