@Override
		public <B> Val<B> map(final Function<? super V, ? extends B> mapper) {
			return new Val<>(mapper.apply(value));
		}
This class represents a constant pattern value, which can be part of a
whole subtree.

@see Var

@param <V> the node value type
@param value the underlying pattern value
jenetics.ext/src/main/java/io/jenetics/ext/rewriting/TreePattern.java