src/main/java/org/fest/assertions/api/Fail.java
public static void fail(String failureMessage, Throwable realCause) {
    AssertionError error = Failures.instance().failure(failureMessage);
    error.initCause(realCause);
    throw error;
  }
public static void fail(String failureMessage, Throwable realCause) {
    AssertionError error = Failures.instance().failure(failureMessage);
    error.initCause(realCause);
    throw error;
  }
Throws an {@link AssertionError} with the given message and with the {@link Throwable} that caused the failure.

@param failureMessage the description of the failed assertion. It can be {@code null}.
@param realCause cause of the error.
@throws AssertionError with the given message and with the {@link Throwable} that caused the failure.