src/main/java/org/fest/assertions/api/Fail.java
public static void failBecauseExceptionWasNotThrown(Class<? extends Throwable> throwableClass) {
    throw Failures.instance().failure(format("Expected %s to be thrown", throwableClass.getSimpleName()));
  }
public static void failBecauseExceptionWasNotThrown(Class<? extends Throwable> throwableClass) {
    throw Failures.instance().failure(format("Expected %s to be thrown", throwableClass.getSimpleName()));
  }
Throws an {@link AssertionError} with a message explaining that a {@link Throwable} of given class was expected to
be thrown but had not been.

@param throwableClass the Throwable class that was expected to be thrown.
@throws AssertionError with a message explaining that a {@link Throwable} of given class was expected to be thrown
but had not been.