in src/main/java/org/junit/internal/runners/ErrorReportingRunner.java [24:35]
public ErrorReportingRunner(Throwable cause, Class<?>... testClasses) {
if (testClasses == null || testClasses.length == 0) {
throw new NullPointerException("Test classes cannot be null or empty");
}
for (Class<?> testClass : testClasses) {
if (testClass == null) {
throw new NullPointerException("Test class cannot be null");
}
}
classNames = getClassNames(testClasses);
causes = getCauses(cause);
}