var nonExtensibleObject = Object.preventExtensions({});
var sealedObject = Object.seal({});
var frozenObject = Object.freeze({});

/**
 * Extensible
 */

assert.extensible({});
assert.notExtensible(nonExtensibleObject);
assert.notExtensible(sealedObject);
assert.notExtensible(frozenObject);

expect({}).to.be.extensible;
expect(nonExtensibleObject).to.not.be.extensible;
expect(sealedObject).to.not.be.extensible;
expect(frozenObject).to.not.be.extensible;

({}).should.be.extensible
nonExtensibleObject.should.not.be.extensible;
sealedObject.should.not.be.extensible;
frozenObject.should.not.be.extensible;

/**
 * Sealed
 */

assert.sealed(sealedObject);
assert.sealed(frozenObject);
assert.notSealed({});

expect(sealedObject).to.be.sealed;
expect(frozenObject).to.be.sealed;
expect({}).to.not.be.sealed;

sealedObject.should.be.sealed;
frozenObject.should.be.sealed;
({}).should.not.be.sealed;

/**
 * Frozen
 */

assert.frozen(frozenObject);
assert.notFrozen({});

expect(frozenObject).to.be.frozen;
expect({}).to.not.be.frozen;

frozenObject.should.be.frozen;
({}).should.not.be.frozen;