Remove the final keyword from private method

[MaicolAntali]

Remove the final keyword from private method. private methods are implicitly final

[eamonnmcmanus]

Ah yes, that other method in #2275 is @SafeVarargs and in the older Java versions we build with such a method must be either static or final. :-( Looks like Java 9 also allows private but we build with Java 8.

[MaicolAntali]

9 also allows private but we build with Java 8.

Precisely, Java 9 has introduced that the SafeVarargs may be used only with private without final

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but we build with Java 8

That's why I closed the PR #2275 and open this one :)