$ javac src/InPackage.java && java demo.mod.InPackage     (25.0.4.1+1-LTS)
[1, 2, 3] from package demo.mod

$ javac src/InPackage.java && java demo.mod.InPackage     (27+35)
[1, 2, 3] from package demo.mod

$ javac -d out --module-source-path multi --module acme.text,demo.app && java -p out -m demo.app/demo.App     (25.0.4.1+1-LTS)
import-module-hello-world

$ javac -d out --module-source-path multi --module acme.text,demo.bad     (25.0.4.1+1-LTS)
multi/demo.bad/demo/Bad.java:7: error: cannot find symbol
        System.out.println(Helper.clean("x"));      // Helper is in the non-exported acme.text.internal
                           ^
  symbol:   variable Helper
  location: class Bad
1 error

$ javac -d out --module-source-path multi --module demo.noreq     (25.0.4.1+1-LTS)
multi/demo.noreq/demo/NoReq.java:3: error: module demo.noreq does not read: java.sql
import module java.sql;       // demo.noreq never says "requires java.sql"
^
1 error

$ javac -d out --module-source-path multi --module acme.text,demo.app && java -p out -m demo.app/demo.App     (27+35)
import-module-hello-world

$ javac -d out --module-source-path multi --module acme.text,demo.bad     (27+35)
multi/demo.bad/demo/Bad.java:7: error: cannot find symbol
        System.out.println(Helper.clean("x"));      // Helper is in the non-exported acme.text.internal
                           ^
  symbol:   variable Helper
  location: class Bad
1 error

$ javac -d out --module-source-path multi --module demo.noreq     (27+35)
multi/demo.noreq/demo/NoReq.java:3: error: module demo.noreq does not read: java.sql
import module java.sql;       // demo.noreq never says "requires java.sql"
^
1 error

$ javac -p lib src/ThirdParty.java     (25.0.4.1+1-LTS)
src/ThirdParty.java:1: error: unnamed module does not read: acme.text
import module acme.text;
^
1 error

$ javac -p lib --add-modules acme.text src/ThirdParty.java && java -p lib --add-modules acme.text -cp out ThirdParty     (25.0.4.1+1-LTS)
a-script-using-a-library-module