The method can be called for an arbitrary array ... section), so the contravariance with Object makes both possible: Java types may be implicitly or explicitly compatible to each other.

This can happen because varargs arguments are implemented as an array, and arrays in Java don’t have the same type-specificity as generics. For instance, consider this method: public static <T ...

Consider this method declaration ... it actually requires us to have a better understanding of Java's type system. But, if you understand how it works, and follow some reasonable style guidelines ...

the object type isn’t required on the left hand side, and if the lambda expression is one line long, both the brackets and the return keyword can be omitted. So a more concise lambda expression that ...