$ perl t1.pl
1..5
ok 1 - mytest1
not ok 2 - sub1-test1
#   Failed test 'sub1-test1'
#   at E:/knob/tm/TMod.pm line 9.
ok 3 - sub1-test2
not ok 4 - mytest3
#   Failed test 'mytest3'
#   at t1.pl line 12.
ok 5 - mytest4
# Looks like you failed 2 tests of 5.