best approach to code hierarchical classes ?

[someone]

On Tuesday, 8 June 2021 at 00:54:41 UTC, someone wrote:
> Are there alternatives to nested classes for such scenarios ?

Self-reply: I created two files for classComputers and 
classComputer and I replaced the nested-classComputer code within 
classComputers with:

import classComputers;

But it won't go:

Error: undefined identifier `classComputer` in module 
`classComputers`, did you mean class `classComputers`?