Message String from SimpleMessage or SimpleError miss apostrophe(')

After created a SimpleError instance like [new SimpleError("It's a demo")], this instance will return the message like "Its a demo", the returned message string missed a apostrophe.
I have know the reason. this is because the MessageFormat class is used in the SimpleMessage class.
The message string always be processed by MessageFormat.format method whether or not there are a number of parameters.
The apostrophe in MessageFormat.format method is a escape character.

So Expected Behavior:
If the message string contain variable like "{0}", this string should be processed by MessageFormat.format method.
Else, the message string should not be processed by MessageFormat.format method.