Suggest tests for nested classes & static methods inside abstracts #1400

[volivan239]

Description

Now if we have an abstract class or interface, we propose for testing all methods that can be invoked statically. Note that we also propose all nested classes (because they may contain static methods, although we do not check that they actually do).

Fixes #1400

Type of Change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Manual Scenario

For the class from listing below, g, Inner and Inner2 were proposed for testing, and tests for g and Inner.f were successfully created:

abstract class MyAbsC {
    abstract int h(int x);
    int f(int x) {
        return 0;
    }
    static int g(int x) {
        return x;
    }
    static class Inner {
        int f(int x) {
            return 1;
        }
    }
    class Inner2 {
        int ff(int x) {
            return h(x);
        }
    }
}

Checklist (remove irrelevant options):

This is the author self-check list

• The change followed the style guidelines of the UTBot project
• Self-review of the code is passed
• The change contains enough commentaries, particularly in hard-to-understand areas
• New documentation is provided or existed one is altered
• No new warnings
• New tests have been added
• All tests pass locally with my changes