Unused import in generated Python code

[mikir]

Consider the following schema:

holder.zs:

package holder;

import list.List;

struct Holder
{
  List(0) list;
};

list.zs:

package list;

subtype bit:5 Param;

struct List(Param param)
{
    varsize num;
};

Then, the generated Python code contains unused import import list.param in module holder.py. Even if this is not a big problem, it would be probably better to improve Python generator not to to generate such unused imports.