Absent Serializable in ancestors for many classes

[CaelmBleidd]

Description

We don't have Serializable in ancestors of java.lang.Long and many other classes that cause false UNSAT verdicts.

To Reproduce

Steps to reproduce the behavior:

1. Run generation on org.utbot.examples.mixed.SerializableExample#example
2. Look at the results

Expected behavior

Should be generated test case.

Actual behavior

There is no test case generated.

Visual proofs (screenshots, logs, images)

public void example() {
    join("string", File.separator, System.currentTimeMillis());
}

public static <T> String join(T... elements) {
    return null;
}

Environment

There is no specific environment required.

Additional context

There is no additional context.