@Override
	public int length() {
		return _genes.length();
	}
Create a new {@code AbstractChromosome} from the given {@code genes}
array.

@param genes the genes that form the chromosome.
@throws NullPointerException if the given gene array is {@code null}.
@throws IllegalArgumentException if the length of the gene sequence is
        empty.
jenetics/src/main/java/io/jenetics/AbstractChromosome.java