[Validator] fixed StaticMethodLoader trying to invoke methods of abstract classes (closes #8589)
removed dead code and fixed CS
merged branch fabpot/dead-code (PR #8572)

This PR was merged into the 2.2 branch.

Discussion
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removed dead code and fixed CS

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
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7d58147 removed dead code and fixed CS