Did you follow the steps of the Connector Guide to install the TestNG package?
Install TestNG Eclipse Plug-in
To run connector unit tests, install the TestNG plug-in in your Eclipse environment.
Follow these steps:
1. Uninstall any existing previous version of TestNG.
2. Start Eclipse and select Help, Install New Software.
The Install page opens.
3. Click Add.
The Add Site page opens
4. Enter TestNG in the Name field, enter http://beust.com/eclipse in the Location field, and click OK.
Information for the plug-in displays in the table on the Install dialog
5. Expand TestNG, select org.testng.eclipse, and click Next twice.
The Review Licenses page opens.
6. Accept the License Agreement and click Finish.
TestNG installs, and Eclipse asks for the permission to restart.
7. Click Yes.
Eclipse restarts, and the TestNG plug-in is now available for use.