src/xblocks/block.js
function accessorsCustomizer(objValue, srcValue) {
    const objSetter = get(objValue, 'set');
    const srcSetter = get(srcValue, 'set');

    return merge({}, objValue, srcValue, {
        set: wrap(objSetter, wrap(srcSetter, wrapperFunction))
    });
}
function accessorsCustomizer(objValue, srcValue) {
    const objSetter = get(objValue, 'set');
    const srcSetter = get(srcValue, 'set');

    return merge({}, objValue, srcValue, {
        set: wrap(objSetter, wrap(srcSetter, wrapperFunction))
    });
}
Inheritance events "set" property changes.
@example
_.mergeWith(objValue, srcValue, accessorsCustomizer);
@param {Object} [objValue] the current value
@param {Object} [srcValue] the new value
@returns {Object}
@private