#16 UnknownCharset and UnsupportedCharset can't recognized by Charset

[jacktan1991]

As we all know, code Charset.forName(String) is to get an Charset instance by a canonical name or an alias.
I tested the following codes

System.out.println(StandardCharsets.UTF_8);
System.out.println(Charset.forName(StandardCharsets.UTF_8.name()));

System.out.println(StandardCharsets.UTF_16);
System.out.println(Charset.forName(StandardCharsets.UTF_16.name()));

As I expected, the result is

UTF-8
UTF-8
true
UTF-16
UTF-16

So I supposed that if I type

Charset.forName(UnknownCharset.getInstance().name())`

OR

Charset.forName("void")

I would get an UnknownCharset instance. But exception happend like

Exception in thread "main" java.nio.charset.UnsupportedCharsetException: void
at java.nio.charset.Charset.forName(Charset.java:536)
at Test.main(Test.java:13)