因为考虑到这一点很有意义.

Because it makes sense when you think about it.

让我用一个小例子来说明:

Let me explain with a small example:

例如，

一个刀片需要一个手柄才能成为 刀".

A knife-blade for example needs a handle for it to be a "knife".

但是手柄不是，需要用小刀作为手柄，对吗?

But a handle doesn't need a knife-blade to be a handle, correct?

using KitchenSet;
using KitchenSet.Knives; // This is where your knives (what uses Blades) would live.
using KitchenSet.Knives.Blades; // The actual blades.