@SuppressWarnings("unchecked")
	static <T> MSeq<T> concat(
		final MSeq<? extends T> a,
		final T... b
	) {
		return ((MSeq<T>)a).append(b);
	}
Return a sequence whose elements are all the elements of the first
sequence followed by all the elements of the vararg array.

@since 5.0

@param a the first sequence
@param b the vararg elements
@param <T> the type of the sequence elements
@return the concatenation of the two inputs
@throws NullPointerException if one of the arguments is {@code null}
jenetics/src/main/java/io/jenetics/util/MSeq.java