static int number(String name)
    {
        return name.length() == 1 && name.charAt(0) == 'Z' ? ID_THROWABLE : 0;
    }
Used when the type is assignable from {@link java.lang.Throwable}.

@author David Yu
@created May 2, 2012
protostuff-runtime/src/main/java/io/protostuff/runtime/PolymorphicThrowableSchema.java