@Override
            public Class<E> enumClass() {
                return delegate.enumClass();
            }
Returns an alternative expression that represents the {@link Enum#name()}
of the enum that would otherwise have been returned by this expression.
<p>
If this expression would have returned {@code null}, then the new
expression will also evaluate to {@code null}.

@return  the name expression
runtime-parent/runtime-compute/src/main/java/com/speedment/runtime/compute/ToEnumNullable.java