YUI.JSON.* vs JSON.* in Node.JS

test.js

var Y = require('yui/json'),
    microtime = require('microtime'),
    i,
    t,
    obj = {
        foo: {
            bar: {
                baz: 'token'
            }
        }
    },
    str = JSON.stringify({
        foo: {
            bar: {
                baz: 'token'
            }
        }
    });

// low level
t = microtime.now();
for (i = 0; i < 100000; i += 1) {
    obj.foo.bar.baz = i;
    JSON.stringify(obj);
}
console.log('stringify native: ', microtime.now() - t);

// yui implementation
t = microtime.now();
for (i = 0; i < 100000; i += 1) {
    obj.foo.bar.baz = i;
    Y.JSON.stringify(obj);
}
console.log('Y.JSON.stringify: ', microtime.now() - t);

// low level
t = microtime.now();
for (i = 0; i < 100000; i += 1) {
    str.replace('token', i);
    JSON.parse(str);
}
console.log('parse native: ', microtime.now() - t);

// yui implementation
t = microtime.now();
for (i = 0; i < 100000; i += 1) {
    str.replace('token', i);
    Y.JSON.parse(str);
}
console.log('Y.JSON.parse: ', microtime.now() - t);