$ java -Xmx3g -XX:-CompactStrings MillionStrings      (JDK 25)
java.version = 25.0.4.1
strings                      : 1,000,000 (average 42.50 chars)
coder == 0 (LATIN1) in set A : 0
coder == 1 (UTF16)  in set B : 1,000,000
A: lower-case ASCII only     : 131,995,184 bytes  (132.0 MB, 132.0 bytes per string)
B: same + one euro sign      : 133,839,824 bytes  (133.8 MB, 133.8 bytes per string)
B / A                        : 1.014