ECHO: "special variable inheritance"
ECHO: 23, 5
WARNING: Ignoring unknown variable 'a'.
ECHO: undef
ECHO: 23, 5
ECHO: "$children scope"
ECHO: "$children should be 1: ", 1
ECHO: "$children should be 4: ", 4
ECHO: "$children should be 1: ", 1
ECHO: "child_module_1 child"
ECHO: "child_module_2 child 0"
ECHO: "child_module_2 child 1"
ECHO: "copy $children"
ECHO: "copy_children_module: ", 2, 2
ECHO: "inner variables shadows parameter"
ECHO: 5, 24
ECHO: "user-defined special variables as parameter"
ECHO: 7
ECHO: 7
ECHO: "assign only visible in children's scope"
WARNING: Ignoring unknown variable 'c'.
ECHO: undef
ECHO: 5
ECHO: "undeclared variable can still be passed and used"
ECHO: 6
ECHO: "attempt to assign from a not-yet-defined variable which also exists globally"
ECHO: 5, 1
