$ java -Xmx3g -XX:+UseCompactObjectHeaders MillionStrings      (JDK 25)
java.version = 25.0.4.1
strings                      : 1,000,000 (average 42.50 chars)
coder == 0 (LATIN1) in set A : 1,000,000
coder == 1 (UTF16)  in set B : 1,000,000
A: lower-case ASCII only     : 86,150,520 bytes  (86.2 MB, 86.2 bytes per string)
B: same + one euro sign      : 130,145,168 bytes  (130.1 MB, 130.1 bytes per string)
B / A                        : 1.511