private EvolutionStart<G, C> start(
		final Supplier<EvolutionStart<G, C>> first,
		final AtomicReference<EvolutionStart<G, C>> other
	) {
		return other.get() != null ? other.get() : first.get();
	}
Create a new concatenating evolution engine with the given list of engines.

@param engines the engines which are concatenated to <em>one</em> engine
@throws NullPointerException if the {@code engines} or one of its
        elements is {@code null}
jenetics.ext/src/main/java/io/jenetics/ext/engine/ConcatEngine.java