The Salesforce Spring'16 released with a long list of changes. As a developer, the changes that most excite me are generally those that are covered in the Development and Deployment categories of the Salesforce release notes.
Test Suites for Apex Test Classes
To create a Test Suite using Developer console : Select Test | New Suite.
Enter a name for your Test Suite.
To choose which classes are in a test suite, select Test | Suite Manager | Your Test Suite | Edit Suite.
Once you select your test classes(it will we more than one also), click on save button. After this to run your test class which you have selected, click on Test | New Suite Run.
Select the Test Suite you want to run and then click on your right corner button "Run Suite".
After clicking on Run Suite, you can see you result here:
Now you have created the test suite and executed your test classes. Isn't that easy..!!
Set and Modify CreatedDate field of the Tests Records
Here is the example of how to use this method.
1: Account a = new Account(name='myAccount');
2: insert a;
3: Test.setCreatedDate(a.Id, DateTime.newInstance(2012,12,12));