src/main/java/org/fest/assertions/Assert.java
protected final @NotNull AssertionError failure(@NotNull String reason) {
    return Fail.failure(formattedErrorMessage(reason));
  }
protected final @NotNull AssertionError failure(@NotNull String reason) {
    return Fail.failure(formattedErrorMessage(reason));
  }
Creates an {@code AssertionError}, adding the description of the actual value to the given message.

@param reason the reason for the failure, used as the message for the thrown exception.
@return the created exception.