$ javac broken/NoPreviewFlag.java     (27+35)
broken/NoPreviewFlag.java:3: error: LazyConstant is a preview API and is disabled by default.
    static final LazyConstant<String> CONFIG = LazyConstant.of(() -> "x");
                 ^
  (use --enable-preview to enable preview APIs)
broken/NoPreviewFlag.java:3: error: LazyConstant is a preview API and is disabled by default.
    static final LazyConstant<String> CONFIG = LazyConstant.of(() -> "x");
                                               ^
  (use --enable-preview to enable preview APIs)
2 errors
exit=1

$ javap -v Basics | grep 'major\|minor'     (27+35, compiled with --enable-preview --release 27)
  minor version: 65535
  major version: 71

$ java Basics     (27+35, without --enable-preview)
Error: LinkageError occurred while loading main class Basics
	java.lang.UnsupportedClassVersionError: Preview features are not enabled for Basics (class file version 71.65535). Try running with '--enable-preview'

$ java --enable-preview Basics     (26.0.2.1+1, class file built by 27)
Error: LinkageError occurred while loading main class Basics
	java.lang.UnsupportedClassVersionError: Basics has been compiled by a more recent version of the Java Runtime (class file version 71.65535), this version of the Java Runtime only recognizes class file versions up to 70.0