@Override
    public Byte apply(ENTITY entity) {
        final V value = field.get(entity);
        if (value == null) return null;
        else return mapper.applyAsByte(value);
    }
Default implementation of {@link FieldToByte}.

@author Emil Forslund
@since  3.1.0
runtime-parent/runtime-field/src/main/java/com/speedment/runtime/field/internal/expression/FieldToByteImpl.java