Bug 72903 Add variable expansion for Test Class in JUnit launch configurations [JUnit]
org.eclipse.jdt.junit/src/org/eclipse/jdt/internal/junit/launcher/JUnitBaseLaunchConfiguration.java
* @inheritdoc 
	 * @param containerHandle
	 * @param pm
	 * @return
	 */
	private IType[] findTestsInContainer(String containerHandle, IProgressMonitor pm) {
		IJavaElement container= JavaCore.create(containerHandle);
		Set result= new HashSet();
		try {
			TestSearchEngine.doFindTests(new Object[]{container}, result, pm);
		} catch (InterruptedException e) {
		}
		return (IType[]) result.toArray(new IType[result.size()]) ;
	}
	public IType[] findSingleTest(IJavaProject javaProject, String testName) throws CoreException {
		IType type = null;
		try {
			type = findType(javaProject, testName);
		} catch (JavaModelException jme) {
			abort("Test type does not exist", null, IJavaLaunchConfigurationConstants.ERR_UNSPECIFIED_MAIN_TYPE); 
		}
		if (type == null) {
			abort("Test type does not exist", null, IJavaLaunchConfigurationConstants.ERR_UNSPECIFIED_MAIN_TYPE); 
		}
		return new IType[]{type};
	}
	
	/**
	 * Throws a core exception with the given message and optional
	 * exception. The exception's status code will indicate an error.