private static String toAlleleTypeName(
			final io.jenetics.PermutationChromosome<?> ch
		) {
			return ch.gene().allele().getClass().getCanonicalName();
		}
Create a writer for permutation-chromosomes. How to write the valid
alleles is defined by the given {@link Writer}.

@param alleleWriter the allele writer
@param <A> the allele type
@return a new permutation chromosome writer
@throws NullPointerException if the given allele {@code writer} is
        {@code null}
jenetics.xml/src/main/java/io/jenetics/xml/Writers.java