readonly a='A'
readonly b='B'
Ok:0

./readonly0.tests: line 19: a: is read only
Fail:2
./readonly0.tests: readonly: line 21: a: is read only
Fail:2

./readonly0.tests: export: line 27: a: is read only
Fail:2

./readonly0.tests: unset: line 44: a: is read only