In layer.go, the CreateSandboxLayer and CreateScratchLayer functions both have a parameter named parentId. It is a natural way to think that this is the parent layer of the layer we want to create, but from line 34 of create.go, we can deduce that the parentId is actually the base layer ID, because the order of paths to read-only parent layers given to wclayer create as argument should ends with base layer. Interestingly, the parentId parameter is ignored inside the CreateSandboxLayer and CreateScratchLayer functions, so it does not make any difference in the execution.

Here, I suggest probably we should delete that parameter. In addition, for argument specifying paths to parent layers like in create, import, export, and mount, we probably need a better documentation on the order and how the list should be given. The order should be ending with base layer instead of starting with it, and the list should have -l before every element like -l layer_3 -l layer_2 -l layer_1.