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));
  }
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.
Creates an { @code AssertionError } adding the description of the actual value to the given message .