There are weird cases when the benchmark state is more cleanly described
by the set of @States, and those @States reference each other. JMH allows
linking @States in directed acyclic graphs (DAGs) by referencing @States
in helper method signatures. (Note that
JMHSample_28_BlackholeHelpers
is just a special case of that.
Following the interface for @Benchmark calls, all @Setups for
referenced @State-s are fired before it becomes accessible to current @State.
Similarly, no @TearDown methods are fired for referenced @State before
current @State is done with it.